Multiplying positive and negative numbers

Difficulty Stretch · Set jmyfkp

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1
(-44)×(-9)=
2
(-72)×43=
3
53×(-90)=
4
(-2)×(-90)=
5
73×(-92)=
6
32×(-86)=
7
(-34)×(-63)=
8
39×(-64)=
9
(-20)×58=
10
(-87)×21=
11
(-39)×60=
12
(-69)×(-12)=
13
63×(-42)=
14
(-25)×46=
15
(-55)×88=
16
(-29)×(-55)=
17
(-7)×74=
18
7×(-63)=
19
(-31)×(-36)=
20
(-90)×(-82)=

What is in this set

The numbers in this set run from 2 to 99.
68% of them have exactly one negative.
33% 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 68% 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 240 different ones, 100% — 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.