Decreasing a number by a percentage

Difficulty Starter · Set a633nx

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

1
A number is 180. Decrease it by 15%.
2
A number is 60. Decrease it by 25%.
3
A number is 60. Decrease it by 12%.
4
A number is 80. Decrease it by 5%.
5
A number is 80. Decrease it by 15%.
6
A number is 100. Decrease it by 30%.
7
A number is 100. Decrease it by 12%.
8
A number is 80. Decrease it by 25%.
9
A number is 200. Decrease it by 30%.
10
A number is 120. Decrease it by 5%.
11
A number is 80. Decrease it by 30%.
12
A number is 160. Decrease it by 25%.
13
A number is 120. Decrease it by 10%.
14
A number is 200. Decrease it by 15%.
15
A number is 100. Decrease it by 12%.
16
A number is 180. Decrease it by 10%.
17
A number is 160. Decrease it by 25%.
18
A number is 120. Decrease it by 20%.
19
A number is 100. Decrease it by 40%.
20
A number is 80. Decrease it by 30%.

What is in this set

The numbers in this set run from 5 to 200.
Every problem in it will go down.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: that is the amount taken off, not the new price — it still has to be taken from 100.
Answers are a whole number.

Drawing 240 problems from this page produced 72 different ones, 30% — 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 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.