DD's Y7 Maths Homework - Help Please

[LadyGlencoraPalliser]

DD has come home with a maths worksheet on directed numbers to complete. Most of it is fairly straightforward eg -13 + -19 etc.
Then we get +15 - -19 which has stumped her and me both. We also can't figure out why some of the questions are partly in brackets eg she has been asked
-16 + (-5) which she assumes is -21
and also (-16) + (-5). Is the answer to this also -21 or does the extra set of brackets mean something different?
She says they didn't cover this in class.
Please can anyone help, maths isn't my strong point, or DH's either.

[peanutbutterkid]

Extra set of brackets doesn't mean anything, it's just there for clarity. Probably to show her how the brackets can help clarify.

15 - -19 = 15 - (-19) = 15 + 19... the minuses cancel out.

[colacubes]

Oh heck, no clue but will ask my ds when he gets in, he is in yr 8. a good tool is the bbc website they have all the cirriculm on there by stages, have look.

www.bbc.co.uk/schools/websites/11_16/site/maths.shtml

i cant do the link thing but theres the address.

[OhWellNeverMind]

Peanut butter is correct though. The brackets are there to distinguish between a number which is negative and the operation of subtracting.

Negative numbers can be easiest to work on a number line...it may seem babyish but helps avoid confusion.

[LadyGlencoraPalliser]

Thanks guys. I will go and explain it to her now. She is keen to get all her homework right - long may it last!