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.