11 Plus Exams Forum

There are 28 in our class.One day there were 6times as many
present
As there were absent.
A.How many were present?
B.How many were absent?

If there were six times as may present as absent, and only one person was absent, how many would be present? How many people would that be overall (the absent person and the present people together)?

Can you get to the answer from there?

I don’t get it please work it out

If one person is absent, how many are present?

A diagram might help you figure it out.

2 columns absent and present.

As streatham mum says

If one person is absent 6 times as many would be present, how many altogether?

This obviously isn’t the right answer..
now try 2 people absent, 6x that many present etc. Notice a pattern in the numbers? How could you make it 28 in total?

This is ratio question.

The ratio of present:absent=6:1

Total is 7 portion, so each portion is 28:7=4

Present is 6 portion=6x4=24

Regards

As an adult I'd do this via ratios but when my dd was doing the 11+ I found this was quite a difficult concept for her to grasp. Her tutor was adamant that it wasn't required and all these questions could be done via trial and error (or "trial and improvement"). So put in 1 or 2 as your answer (for example), work it out and then keep going till you get to the right one.

This is how I would have explained it to dd when she was learning this:
Suppose you had a class where there were 6 children there and one not there, how many children would there be in that class?
Draw it out with 6 blue and one red dot.

However there are not 7 children in the class, there are 28. If we had twice as many, how many children would we have. Again draw the dots and line them up in cloumns. Still mot enough. So how many lots of 7 children would we need to make 28?

Draw it out with lines of dots. So for every group of 7 dots there are 6 blue and 1 red and you have 4 groups.

Do a few like this until your child gets the hang of it, as they do not want to be drawing out 28 dots and colouring them in in the 11+.

I've just realised my method is more or less the same as Yoyo said. Doing it this way will help build an understanding of maths; more than just by trial and error or scribbling down numbers. It important to get children to visualise and understand, rather than just learn methods.

russet wrote:I've just realised my method is more or less the same as Yoyo said. Doing it this way will help build an understanding of maths; more than just by trial and error or scribbling down numbers. It important to get children to visualise and understand, rather than just learn methods.

Absolutely, I am a great believer in diagrams and manipulatives. Understanding why you are doing something makes it easier to transfer that skill to other examples.