A fraction times a whole number

Difficulty Starter · Set 3gx82b

Fill in what you can and press Check. Nothing you type is sent anywhere.

1
23×9=
2
15×4=
3
78×2=
4
58×12=
5
25×4=
6
13×11=
7
34×8=
8
12×2=
9
18×5=
10
23×2=
11
57×6=
12
25×10=
13
14×9=
14
45×4=
15
13×4=
16
14×6=
17
17×10=
18
12×12=
19
12×7=
20
12×3=

What is in this set

The numbers in this set run from 1 to 12.
Every problem in it will have a whole number on one side.
40% of them need simplifying at the end.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: the whole number multiplied the top and the bottom; multiplying by a whole number takes that many of the parts, so only the numerator grows.
Answers are a fraction in its lowest terms, written like 3/4.

Drawing 240 problems from this page produced 129 different ones, 54% — so a sheet of 20 will come back to a problem you have seen — there are only so many sensible ones of this kind.

The same skill, harder or easier

We would put this in front of a grade 4 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.