Filling in an equivalent ratio

Difficulty Starter · Set 9xn6wx

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

1
Fill in the missing number: 6 : 3 = 18 : ?
2
Fill in the missing number: 6 : 8 = 12 : ?
3
Fill in the missing number: 2 : 3 = 6 : ?
4
Fill in the missing number: 2 : 3 = 4 : ?
5
Fill in the missing number: 9 : 3 = 18 : ?
6
Fill in the missing number: 5 : 5 = 15 : ?
7
Fill in the missing number: 7 : 3 = 14 : ?
8
Fill in the missing number: 5 : 7 = 15 : ?
9
Fill in the missing number: 6 : 4 = 18 : ?
10
Fill in the missing number: 2 : 7 = 6 : ?
11
Fill in the missing number: 4 : 5 = 8 : ?
12
Fill in the missing number: 4 : 8 = 8 : ?
13
Fill in the missing number: 4 : 4 = 8 : ?
14
Fill in the missing number: 8 : 4 = 24 : ?
15
Fill in the missing number: 9 : 9 = 18 : ?
16
Fill in the missing number: 8 : 7 = 16 : ?
17
Fill in the missing number: 3 : 8 = 6 : ?
18
Fill in the missing number: 8 : 2 = 16 : ?
19
Fill in the missing number: 5 : 9 = 10 : ?
20
Fill in the missing number: 5 : 7 = 15 : ?

What is in this set

The numbers in this set run from 2 to 27.
Every problem in it will scale a whole ratio up.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 85% of the problems: the left side grew by 4 and the same was added on the right.
Answers are a whole number.

Drawing 240 problems from this page produced 102 different ones, 43% — 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 6 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.