Putting a number into an expression

Difficulty Stretch · Set ag170v

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1
If x = -5, work out5x+19=
2
If x = 4, work out2x+9=
3
If x = -12, work out2x+17=
4
If x = -8, work out11x+20=
5
If x = 10, work out14x+14=
6
If x = 14, work out12x+6=
7
If x = -5, work out8x+20=
8
If x = 6, work out12x+12=
9
If x = 9, work out14x+11=
10
If x = -3, work out8x+14=
11
If x = -12, work out14x+14=
12
If x = -4, work out9x+17=
13
If x = -9, work out14x+10=
14
If x = 8, work out5x+10=
15
If x = 8, work out6x+13=
16
If x = -2, work out6x+9=
17
If x = 8, work out12x+4=
18
If x = -5, work out9x+12=
19
If x = 10, work out10x+20=
20
If x = -12, work out12x+11=

What is in this set

The numbers in this set run from 2 to 20.
53% of them substitute a positive number.
47% of them substitute a negative number.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: 3x means 3 × x, so with x = -7 it is -21, not the two digits written next to each other.
Answers are a whole number.

Drawing 240 problems from this page produced 233 different ones, 97% — 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.