The missing numerator in an equivalent fraction

Difficulty Starter · Set jpr2n6

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1
34=?8— what is the numerator?
2
13=?15— what is the numerator?
3
23=?9— what is the numerator?
4
18=?48— what is the numerator?
5
12=?6— what is the numerator?
6
12=?6— what is the numerator?
7
12=?8— what is the numerator?
8
18=?24— what is the numerator?
9
12=?8— what is the numerator?
10
13=?12— what is the numerator?
11
34=?20— what is the numerator?
12
23=?15— what is the numerator?
13
17=?14— what is the numerator?
14
27=?28— what is the numerator?
15
14=?12— what is the numerator?
16
34=?16— what is the numerator?
17
23=?18— what is the numerator?
18
14=?24— what is the numerator?
19
16=?18— what is the numerator?
20
34=?8— what is the numerator?

What is in this set

The numbers in this set run from 1 to 48.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: the denominator grew by 16 and the same amount was added on top.
Answers are a whole number.

Drawing 240 problems from this page produced 93 different ones, 39% — 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.