Decreasing a number by a percentage

Difficulty Stretch · Set vg885b

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

1
A number is 1200. Decrease it by 15%.
2
A number is 840. Decrease it by 10%.
3
A number is 700. Decrease it by 15%.
4
A number is 1000. Decrease it by 40%.
5
A number is 680. Decrease it by 12%.
6
A number is 740. Decrease it by 40%.
7
A number is 80. Decrease it by 20%.
8
A number is 540. Decrease it by 20%.
9
A number is 480. Decrease it by 12%.
10
A number is 460. Decrease it by 40%.
11
A number is 540. Decrease it by 20%.
12
A number is 780. Decrease it by 5%.
13
A number is 440. Decrease it by 40%.
14
A number is 140. Decrease it by 10%.
15
A number is 860. Decrease it by 15%.
16
A number is 380. Decrease it by 12%.
17
A number is 940. Decrease it by 5%.
18
A number is 580. Decrease it by 20%.
19
A number is 720. Decrease it by 40%.
20
A number is 40. Decrease it by 40%.

What is in this set

The numbers in this set run from 5 to 1,200.
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 1200.
Answers are a whole number.

Drawing 240 problems from this page produced 184 different ones, 77% — 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.