Putting a number into an expression

Difficulty Standard · Set 9o6kzn

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1
If x = 12, work out4x+14=
2
If x = 2, work out2x+8=
3
If x = 13, work out10x+10=
4
If x = 13, work out2x+10=
5
If x = 10, work out7x+4=
6
If x = 7, work out7x+13=
7
If x = 3, work out2x+8=
8
If x = 12, work out7x+16=
9
If x = 7, work out8x+7=
10
If x = 12, work out2x+7=
11
If x = 5, work out9x+10=
12
If x = 13, work out7x+8=
13
If x = 3, work out3x+15=
14
If x = 8, work out4x+12=
15
If x = 13, work out8x+8=
16
If x = 6, work out2x+16=
17
If x = 6, work out10x+4=
18
If x = 6, work out6x+4=
19
If x = 6, work out9x+12=
20
If x = 6, work out2x+13=

What is in this set

The numbers in this set run from 2 to 16.
Every problem in it will substitute a positive number.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: 5x means 5 × x, so with x = 13 it is 65, not the two digits written next to each other.
Answers are a whole number.

Drawing 240 problems from this page produced 225 different ones, 94% — 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 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.