Year 7 maths help

[PollyRuby]

I can do these questions but can't explain them to my son. Are they looking for him to work out e.g. 10% then he can get to
What 40% is type thing ?
As for 15% of (mystery number ) = 27
Help. I got an A at GCSE but cannot think straight with migraine today and we are arguing as he hates it and "doesn't get it mum". Argghhh

Pic added of the questions. Be kind please as he's struggling Thank you

Try again

Did you mean to attach a picture?

Taking your example,

15% of something is 27.

If 15% = 27
Then
5% = 27 divided by 3 which is 9.

If 5% is 9 then 100% is 9 x 20 which is 180

Ok so decrease 80 by 15% means

Find 15% of 80 and then take it away

So
100% = 80
10% = 8
5% = 4

So 15% is 12

80. -12 is 68

Express 28 to 35 as percentage change

Percentage change is

Change divided by original number

35 - 28 = 7.

So the change is 7.

7 divided by 28 is one quarter which is 25% as a percentage

As a teacher (not Maths, sorry) I would always tell my pupils to have a go and let me know if they were struggling. If he hands it in with the correct answers they the teacher will assume he understands. I’d pop a note on the bottom of the sheet to say that you have tried to help him but he needs the teacher to go back over it with him.

For question A it looks like you've made a mistake. 52/100 would simplify down to 26/50 or 13/25, but not 26/25.

C,E&G look good.

If this is secondary the chance of the teacher going back over it with him is basically nil.

He might get emailed a video on percentages.

(Secondary maths teacher for many years)

For B you're pretty much there, your logic is spot on, but it asks for percentage not fraction so you should write 45% instead of 45/100.

This is saddening to read but I get it. I feel I'll have to learn it all again.

Thanks all. He got to working out some of it once the upset had passed and the feeling of not being able to do it AT ALL had passed. Managed to figure out if he knew 5% or 10% he could work out other percentages
Thank you all for helping. It's very stressful

Good that he has understood that by working out 10% and 5% he can figure out other percentages.

For E and G he has to show workings.

F not completed, but it is usually easier to start with 10% followed by 5% and then make up the total using these.

10% = 800, 5% = 400, then 35% = (800 x 3) + 400

For I, 10% would be 11, and from that he can figure out that 11 x 7 = 77, then it must be 10% x 7, which is 70%.

For J, it is important to remember that % change is always based on the ORIGINAL amount (28 in this case). So an increase of 7 based on 28 works out at an increase of 25% as has been pointed out.