to think this was an unfair way to select children

[3boys40]

Given a number between 2 and 12 starting at the front of class. Than rolling a dice to select said children. You would think a maths teacher should know that gives certain children an unfair advantange. My poor ds who sits at the the front had no chance with 2.

The OP said A Dice - so I took that to mean one dice.

if more than one, then yes, the odds will be different (factors? )

X post.

Yes you others are right, but the op specified 'a dice'. Unless its a test if some sorts. Can't imagine a normal person getting so get up about this.

Ah cross posts.

Thought I was going mad there

It's one die or two (or more) dice. So "a dice" is wrong either way

Schools do have fancy dice, so may have been 12 sided (though in that case why miss out number 1?)

Otherwise I despair of posters above who don't realise that with 2 dice the chance of scoring a total of 2 is 1 in 36, whereas the chance of scoring a total of 7 is 1 in 6.

sorry yes it was 2 of them.

Ahhh yeh if there was 2 dice ... That is unfair then

Rolling two dice means 7 is most likely to come up.

X posts with millions on others.

I still believe the probability is the same, if your number is 7 and you roll a 4, the other number MUST be a 3...

I don't know

sorry used dice to mean 2 but shouldn't have said a

I guess that would depend if the dice were rolled at the same time, or one after the other as well?

Total on dice Pairs of dice Probability
2 1+1 1/36 = 3%
3 1+2, 2+1 2/36 = 6%
4 1+3, 2+2, 3+1 3/36 = 8%
5 1+4, 2+3, 3+2, 4+1 4/36 = 11%
6 1+5, 2+4, 3+3, 4+2, 5+1 5/36 = 14%
7 1+6, 2+5, 3+4, 4+3, 5+2, 6+1 6/36 = 17%
8 2+6, 3+5, 4+4, 5+3, 6+2 5/36 = 14%
9 3+6, 4+5, 5+4, 6+3 4/36 = 11%
10 4+6, 5+5, 6+4 3/36 = 8%
11 5+6, 6+5 2/36 = 6%
12 6+6 1/36 = 3%

Oh that formatted all wrong, I copied and pasted.

but if you have 2 the only hope is if you get a 1 and a 1.
4 could be 3 and 1 2 and 2etc

Did the teacher explain this to the children? Was it a way of demonstrating probability? Or did they just 'choose' and leave it at that?

Total on dice Pairs of dice Probability
2: 1+1, 1/36 = 3%
3:1+2, 2+1, 2/36 = 6%
4: 1+3, 2+2, 3+1, 3/36 = 8%
5:1+4, 2+3, 3+2, 4+1, 4/36 = 11%
6:1+5, 2+4, 3+3, 4+2, 5+1, 5/36 = 14%
7:1+6, 2+5, 3+4, 4+3, 5+2, 6+1, 6/36 = 17%
8: 2+6, 3+5, 4+4, 5+3, 6+2, 5/36 = 14%
9:3+6, 4+5, 5+4, 6+3, 4/36 = 11%
10:4+6, 5+5, 6+4, 3/36 = 8%
11:5+6, 6+5,2/36 = 6%
12:6+6,1/36 = 3%

depends what he was selecting them for. was he demonstrating probability?

What are they being selected for? If it was just a maths lesson YABU- if it was for a part in the nativity YANBU

Obviously the child who has number 7 has the best chance of being selected, with 2 & 12 the least.
But, given it's a maths teacher, I rather suspect that was the point if the exercise. Unless she/he is really thick.

It was to help out at parents evening. He really wanted to do it as his brother was coming and maths is by far his favourite and best subject. Most other subject teachers picked their form students (even less fair!!!)o he was completely overlooked despite volunteering.

Not understanding the big deal here... Surely the MATHS teacher was just using this as a way to teach maths?? If they used this method to pick people for sports then that's a little different. Somebody has to have the numbers 2 or 12... Life's unfair like that

Dice is plural, die is singular

Yes you would expect a maths teacher to realise that was unfair. But unless it was selection for something really good maybe he/she didn't think it was important enough to go to too much trouble to ensure equal odds.