Maths homework help.

[DerektheWonderdog]

DD, Yr7, is struggling on this question, if anyone could help?

The monthly charge for a mobile phone is C=5m+1000 where C is the charge in pence and m is the number of minutes spent on the phone. Work out the monthly charge in a month where 300 minutes are spent on calls.

I thought I was reasonable at maths but this is hurting my head 🙄

C= 5x100+1000?
500+1000
1500pence
= £15

5 x 300 +1000
= 1500 + 1000
= 2500
That is pence so £25

C=5x300+1000 surely?

You are just substituting 300 for m in the original formula.

Thanks pixie, that's what I thought but it doesn't account for the 300 minutes? Unless it's 5x 300 + 1000 = 2500 = £25?

Thank you all! Yes, so £25? Do you want another? 😁

"Write an expression that is 4 less than b"

Yup, it’s that.

B-4

C=5x300+1000= 2500. Which is pence- so £25.

Be a bit careful about still doing homework at 8.30 in year 7- he will get so tired.

b - 4

m is minutes spent on the phone. m is 300.

The charge is 5m +1000, which is 5×m +1000.

5m= 5 × 300 = 1500
1500 + 1000 = 2500 pence
2500 ÷100 = £25

The first one is £25. The second question is a bit lacking in context. Is that the whole thing? Given just what you’ve written, I’d go for something like:

y = b - 4

It’s asking for an expression so there should be no ‘=‘ in it.

Be a bit careful about still doing homework at 8.30 in year 7- he will get so tired.

Sounds like MNers are doing it for him...

Bertrand it's ok, DD did it much earlier and I said to leave that one. She's in bed now and I was sitting puzzling over it so thought I'd ask the wise folk of Mumsnet. I'll show her in the morning.

Thanks breathlessness, I thought it was harder than that. But I get the key word 'expression'. Feel a bit stupid now.

Thank you everyone. I really appreciate it.

“Sounds like MNers are doing it for him...“

Good.

titchy DD did the other 28 by herself but thanks for your input.

Sorry I totally mistyped the first expression I did as 100 instead of 300

Thanks pixie and everyone else. I'm usually quite hands off with homework and DD was previously confident in maths but secondary school has knocked the wind out of her sails a bit so I just wanted to be able to help her.

Khan Academy has some good videos for difficult bits in maths. If there are bits she struggles with, a good plan is to walk away from it. For some reason, maths is always easier when you have a break then come back to it.

Those two questions are just about introducing the concept of algebra and getting familiar with termonology.

I help a girl who was getting h/w sounding the same in y7. The same type of question came up regularly, so if they learn what it means one week, then hopefully next time they understand it.

I think some people get confused by the fact that '5m' is the same as 5 × m. Then there's the whole letters representing numbers can cause panic. But algebra is a beautiful thing, once that's clear.

Mine has been covering this topic. School uses Hegarty maths for homework, where they watch a video , make notes then do the quiz. He has mentioned that some of his maths set s seemed to take a while to grasp it and I think this sort of abstract thinking is a step up from primary, but once it clicks algebra is lovely.

JustRichmal I'll have a look at Khan videos, thank you.
TeenplusTwenties yes I think that's the thing. It's a new concept but once she 'gets' it then it'll seem less daunting.
Lougle yes, just understanding that it's actually a x is a big help.
HeartyHooker I'll have a look at Hegarty maths. I think the teacher is just setting homework without having taught them the concept first so it's more like a formative assessment rather than checking learning. The don't even have to hand it in, it's peer marked so the teacher has no idea how they got on anyway.
DD struggled with maths in the lower years of primary but really clicked with it in yr5 and 6. But now I feel like it's slipping away from her again.
All the advice on here has been really useful, thank you and has given me some pointers to be able to steer her in the right direction without making it into a 'thing'.