Multiplying positive and negative numbers

Difficulty Starter · Set zz3753

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1
(-6)×11=
2
(-7)×(-2)=
3
2×(-5)=
4
(-5)×10=
5
(-8)×(-5)=
6
12×(-2)=
7
(-9)×10=
8
8×(-11)=
9
(-9)×2=
10
(-5)×(-7)=
11
(-11)×3=
12
2×(-10)=
13
6×(-11)=
14
(-9)×11=
15
(-7)×5=
16
(-9)×(-4)=
17
(-5)×9=
18
(-2)×10=
19
(-12)×(-10)=
20
(-11)×(-5)=

What is in this set

The numbers in this set run from 2 to 12.
70% of them have exactly one negative.
30% of them have a negative on both sides.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 70% of the problems: the sign came out wrong: one negative and one positive give a negative.
Answers are a whole number.

Drawing 240 problems from this page produced 180 different ones, 75% — so a sheet of 20 is a new sheet almost every time.

The same skill, harder or easier

We would put this in front of a grade 7 class. That is our judgement, not a standard, and it is printed here so you can disagree with it. Everything else we put in that year.