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26 August 2007, 19:51
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#1
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Member
Country: UK - England
Town: East Sussex
Boat name: Bfor
Make: Jeanneau
Length: 9m +
Engine: Yanmar 3gm30
Join Date: Jul 2007
Posts: 184
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Ribs and 'rithmetic. (For instructors really, but all welcome)
As a novice instructor, I keep making discoveries of things that students find tricky, which I suspect that most RIB owners would take for granted.
The main area of failure with the students seems to be Maths?Algebra.
To keep things simple when we do passage planning, I make them work out a short course where the legs are perhaps 1.5 to 2.5 miles each.
I then get them to give me a couple of possible cruising speeds - and the usual answers given are 20kts and 30kts.
Now comes the "tricky" bit. I ask them to work out the time each leg will take. (In conjunction with the time/distance table in an almanac if they need it).
Those who use the almanax table normally get the correct answer but needless to say it takes a fair while!
I think at the moment, almost none of the others have got anywhere near the correct answer by using their heads, or phones, or PDAs or other gizmos. In one case, I had a 3.5 mile leg at 30 kts taking a suggested 40 minutes!!
When they "fail" the maths, I usually refer them to the almanac and then go through the routine of "60kts = 1 nm per minute, so 30kts is 1 nm per 2 minutes, 20 kts is 1 nm per 3 minutes etc etc". Even this is sometimes met with looks of concern until you explain in a little more depth.
Out of interest, who else finds the above surprising when most of the clients drive cars and surely must have some idea that 60mph equals a mile a minute.
The next thing that surprises me is that the greater majority have no idea how many degrees are in a right angle, and even less of how many degrees are in a full circle!!
Again, I find this pretty amazing and normally draw a picture on the board and annotate it accordingly.
Or am I just expecting too much from those doing a basic PB course?
Thanks for your input, in advance.
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26 August 2007, 20:03
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#2
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Member
Country: Other
Town: Stanley, Falkland Is
Boat name: Seawolf
Make: Osprey Vipermax 5.8
Length: 5m +
Engine: Etec 150
Join Date: Mar 2006
Posts: 3,726
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all seems like common sense to me and I knew all of those things!
__________________
A Boat is a hole in the water, surrounded by fibreglass, into which you throw money...
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26 August 2007, 21:37
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#3
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Member
Country: UK - England
Town: East Sussex
Boat name: Bfor
Make: Jeanneau
Length: 9m +
Engine: Yanmar 3gm30
Join Date: Jul 2007
Posts: 184
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Thats pretty much what I thought too.
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26 August 2007, 21:38
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#4
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Member
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
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May I ask what age range the typical culprits belong to - or are they all the same???
It never ceases to amaze me how thick many people can be. I was talking to a group of people the other day and commented on how some people don't even know if the Moon goes around the Earth or the Sun - many in the group had to stop and think as well.......
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26 August 2007, 21:43
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#5
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Member
Country: UK - England
Town: East Sussex
Boat name: Bfor
Make: Jeanneau
Length: 9m +
Engine: Yanmar 3gm30
Join Date: Jul 2007
Posts: 184
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Ive had as young as 14 and as "old" as 50.
(Would that I was as young as 50........ ![mad](https://www.rib.net/forum/images/smilies/mad.gif) )
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26 August 2007, 21:44
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#6
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exspyrd trayd membir
Country: Ireland
Town: inn wiliks hed
Make: Redbay 6.5
Length: 6m +
Engine: Twin Etec 90hp
Join Date: Aug 2003
Posts: 962
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Quote:
Originally Posted by codprawn
some people don't even know if the Moon goes around the Earth or the Sun
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itt gows arownd bowf yew nobbend.
yew mite bee avin a clowse upp luk at de awbits ov de planits wen dat bastud fewze onn de semtix deesides too werk.
gaRf
__________________
luk arfter numbir wan, downt stepp inn numbir too
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26 August 2007, 22:00
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#7
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Member
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
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Wonder how she would cope with the finer points of navigation???
You just MUST watch this............
Where's that semtex when you need it Garf - I used the last lot for a spot of fishing!!!
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26 August 2007, 22:03
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#8
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Member
Country: UK - England
Town: Scillies
Boat name: Freedom
Make: Searider
Length: 5m +
Engine: Yam 2st 90
Join Date: Jan 2007
Posts: 335
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Sorry but most people (especially the younger 25 & less ![flame](https://www.rib.net/forum/images/smilies/flame.gif) ) REALLY struggle with BASIC mental arithmetic. Your comment does not surprise me at all. Until people are forced to use the most complete computer in the world (our brain) this will not change. Take away the calculators and PDAs and get people to use their brains.
Rant over.
Seriously I am all for assistance with all things and am a techno geek myself. BUT, you must be able to back it all up with basics. Otherwise you are taking unreasonable risks with yourself and others. At the risk of getting flamed - I suspect there are more problems caused by incompetence than by drunkeness.
And yes I have had to call for assistance myself.
walruz.
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26 August 2007, 22:30
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#9
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Member
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 5,596
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Quote:
The next thing that surprises me is that the greater majority have no idea how many degrees are in a right angle, and even less of how many degrees are in a full circle!!
Again, I find this pretty amazing and normally draw a picture on the board and annotate it accordingly.
Or am I just expecting too much .....
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Quote:
all seems like common sense to me and I knew all of those things!
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Welcome to the world of above average intelligence. Let's not deride those who have a little more difficulty though.
__________________
JW.
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27 August 2007, 01:49
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#10
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Member
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,562
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Quote:
Originally Posted by jwalker
Welcome to the world of above average intelligence. Let's not deride those who have a little more difficulty though.
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Agreed, but would you think most people have had no practice at mental calculations because they always use calculators!
PeterB give your stoodents a break tell em what the speed is in Knots per hour and then tell em what it is in Knots per minute. That technique usually enables people to be accurate
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
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27 August 2007, 07:33
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#11
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Member
Country: UK - England
Town: Poole
Length: 6m +
Join Date: May 2000
Posts: 406
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As Instructors our role is to develop knowledge and capability in those we are working for being very mindful that people will vary in their ability to grasp certain of the areas that we are covering.
It then becomes our job to ensure that we explain these concepts in such ways that people have the greatest chance of grasping them. We will need to have a variety of ways available to explain some of the areas.
I feel that it is unreasonable & unrealistic to expect those coming on courses to be able to do these sort of calculations easily. In my opinion whether you are able to or not is a product of a variety of things not least of all whether you have to use your brain daily for such tasks, if you don’t then inevitably it will take more time to engage with such concepts.
We regularly work with people who certainly struggle with numbers, perhaps cannot read and write and might for whatever reason be very practical people whilst really struggling with some other areas. Indeed a high number of the people that we teach have dyslexia making certain areas more difficult for them than others. And these people are just a standard cross section of those taking Level 2 and other courses, they are no less capable than others they just have different strengths – and often are amongst the best boat handlers. I don’t believe it is very helpful if we as Instructors create the impression that not being able to grasp such subjects implies people are at best less capable than others.
In the overall scheme of things bear in mind that grasping such subjects is not that important in the context of what we are trying to achieve at Level 2. The fundamental aim of Level 2 is to ensure that people can handle a boat safely and have a basic appreciation of a variety of other areas.
As to the subject of speed/time/distance calculations I used to really struggle in the heat of the moment to work out the numbers (and consulting an almanac isn’t always a very realistic option) until someone explained the following way of doing things to me:
Take an example, I’m doing 15 knots. Therefore in 60 mins I’m going to travel 15 miles.
Divide by 10
In 6 minutes I’ll do 1.5 miles.
How long will it take me to do 8 miles?
That’s 5 lots of 1.5 miles (to give 7.5miles) with 0.5 miles left over. 0.5 miles will take 2 mins (1/3 of 6 mins) and the 7.5 miles will take 30 mins (5 x 6 mins) so 32 mins.
And finally, does it feel right. 32 mins to do 8 miles at 15 knots – seems okay.
Regards
Paul
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27 August 2007, 07:59
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#12
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Member
Country: UK - England
Town: Portishead/Falmouth
Make: Ribeye
Length: 5m +
Join Date: Jan 2007
Posts: 161
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Quote:
Originally Posted by Rogue Wave
tell em what the speed is in Knots per hour and then tell em what it is in Knots per minute.
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Technically a 'knot per hour' would be a unit of acceleration, not speed!
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27 August 2007, 08:10
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#13
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Member
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,562
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Well spotted
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
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27 August 2007, 08:45
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#14
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Member
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 5,596
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Quote:
Originally Posted by Paul Glatzel
As Instructors our role is to develop knowledge and capability in those we are working for being very mindful that people will vary in their ability to grasp certain of the areas that we are covering.
It then becomes our job to ensure that we explain these concepts in such ways that people have the greatest chance of grasping them. We will need to have a variety of ways available to explain some of the areas.
I feel that it is unreasonable & unrealistic to expect those coming on courses to be able to do these sort of calculations easily.
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I agree and that's a nice open minded view.
Quote:
Take an example, I’m doing 15 knots. Therefore in 60 mins I’m going to travel 15 miles.
Divide by 10
In 6 minutes I’ll do 1.5 miles.
How long will it take me to do 8 miles?
That’s 5 lots of 1.5 miles (to give 7.5miles) with 0.5 miles left over. 0.5 miles will take 2 mins (1/3 of 6 mins) and the 7.5 miles will take 30 mins (5 x 6 mins) so 32 mins.
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But that's still fairly complex for folk with limited arithmetic skills.
Quote:
Originally Posted by waver
..but would you think most people have had no practice at mental calculations because they always use calculators!
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I've no doubt that my brain has become slower as a result of lack of practise but to use a calculator one still needs to understand the principle of the solution, eg. what is ¼ of 28 requires the understanding that 28 must be divided by 4. In Paul's example it needs to be understood that dividing 60 by 15 and then multiplying it by 8 gives the solution. His method of explanation is an attempt to surmount this part of the problem. So yeh, I agree but removing calculators won't fix it...how the fek would I manage me calculations then?
__________________
JW.
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27 August 2007, 09:05
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#15
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Member
Country: UK - England
Town: Bursledon
Boat name: Mustard
Make: Ribeye 785
Length: 7m +
Engine: Yamaha 200/Merc 6
MMSI: 235068693
Join Date: Oct 2006
Posts: 618
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Quote:
Originally Posted by Rogue Wave
Agreed, but would you think most people have had no practice at mental calculations because they always use calculators!
PeterB give your stoodents a break tell em what the speed is in Knots per hour and then tell em what it is in Knots per minute. That technique usually enables people to be accurate
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Knots per hour??
Knots per minute??
Don't you mean Nautical miles?
Knots per hour is an accelleration!
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27 August 2007, 09:16
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#16
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Member
Country: UK - England
Town: East Sussex
Boat name: Bfor
Make: Jeanneau
Length: 9m +
Engine: Yanmar 3gm30
Join Date: Jul 2007
Posts: 184
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Quote:
Originally Posted by Paul Glatzel
As to the subject of speed/time/distance calculations I used to really struggle in the heat of the moment to work out the numbers (and consulting an almanac isn’t always a very realistic option) until someone explained the following way of doing things to me:
Take an example, I’m doing 15 knots. Therefore in 60 mins I’m going to travel 15 miles.
Divide by 10
In 6 minutes I’ll do 1.5 miles.
How long will it take me to do 8 miles?
That’s 5 lots of 1.5 miles (to give 7.5miles) with 0.5 miles left over. 0.5 miles will take 2 mins (1/3 of 6 mins) and the 7.5 miles will take 30 mins (5 x 6 mins) so 32 mins.
And finally, does it feel right. 32 mins to do 8 miles at 15 knots – seems okay.
Regards
Paul
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My few courses have taught me that its unrealistic to expect them to be able to do it Paul. It just came as a bit of a small surprise!
However, I now work out three figures for them on the board and make sure that they understand the logic behind these by starting at 60 knots.
30 knots = 2 minutes per nm
20 = 3 mins per nm
15 = 4 mins per nm
That way they can just multiply the passage distance by 2, 3 or 4 and get the correct time for the trip.
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27 August 2007, 10:11
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#17
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Member
Country: UK - England
Town: NW& wherever the boat is!
Boat name: depends on m'mood!
Make: Humbers/15-24m cats
Length: 6m +
Engine: etec130/big volvos
MMSI: many and various
Join Date: Nov 2001
Posts: 1,816
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when you spend so much of your time on a boat- be it a 6m rib or a 16m twin 1,000 hp cat- as we do it is far too easy to forget that folk coming on a boat course are often in a state of nervousness ( ok in some cases fear!) of what is ahead of them. To some it is to be their first taste of being at the wheel of a high speed craft (or perhaps any boat at all) and some have not been to sea before except on perhaps a cross channel ferry. This fear manifests itself in different ways. The overtalkative guy who keeps telling you he has done this that and the other is just basically scared of making a prat out of himself, and the quiet client who wants to shrink away from being noticed is just showing his nervousness in another way. When they are in this sorta state basic maths is just a step too far, especially if you are gonna remind them of their school days with a blackboard and chalk!! By day two when they have been out in the boats, realise how much they really do love it despite all their prior misgivings and doubts then you may find them more responsive and with more brain cells than you originally credited them with, particularly if it is now more relevant and they can see where they have been the day before on the chart and how long it did actually take. It is very easy to be the smart alec when instructing on the bit of water that you always use and where time and distance is obvious to you but a bit of empathy with the total novices goes a long way to building their confidence instead of destroying it with sums. Oh yes and I think the total lack of ability to do simple mental arithmetic is a shamefull indictement of our education system
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27 August 2007, 10:21
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#18
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Member
Country: UK - Isle of Man
Town: Douglas
Length: no boat
Join Date: Aug 2006
Posts: 339
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Now I know why I promote Paul Gs Powerboat Handbook to all my Level 2 students, he really has got a fantastic way of putting concepts across in an easily understood manner. I also fully support his view that maybe the issues being discussed on this thread are not of huge importance within the Level 2 programme, safe boat handling must be foremost!!
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27 August 2007, 12:19
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#19
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Member
Country: UK - England
Town: East Sussex
Boat name: Bfor
Make: Jeanneau
Length: 9m +
Engine: Yanmar 3gm30
Join Date: Jul 2007
Posts: 184
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Quote:
Originally Posted by Cypman
Safe boat handling must be foremost!!
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Yep!
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27 August 2007, 12:50
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#20
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exspyrd trayd membir
Country: Ireland
Town: inn wiliks hed
Make: Redbay 6.5
Length: 6m +
Engine: Twin Etec 90hp
Join Date: Aug 2003
Posts: 962
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Quote:
Originally Posted by wavelength
folk coming on a boat course are often in a state of nervousness ( ok in some cases fear!)
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i fink yorr rite mistir mullitt.
i noe a nobbur hoo wennt onn a corse an hee sed fuk mee gaRf de teecher waz a scairy buggir. hee ad a faice dat ownly a muvver cud luv an dats ifn sheez parshully sited
gaRf
dis iz a pik ov de aformenshund teecher. i av ad itt reetuched too maik im a bitt mor preezentabul
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luk arfter numbir wan, downt stepp inn numbir too
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