It also works for subtracting numbers near the same tens value.
Here’s another:
Test yourself
Try these for yourself:
a) 13 − 8 =
b) 17 − 8 =
c) 12 − 9 =
d) 12 − 8 =
e) 124 − 88 =
f) 161 −75 =
g) 222 − 170 =
h) 111 − 80 =
i) 132 − 85 =
j) 145 − 58 =
How did you go? They are easy if you know how. Here are the answers:
a) 5
b) 9
c) 3
d) 4
e) 36
f) 86
g) 52
h) 31
i) 47
j) 87
If you made any mistakes, go back and read the explanation and try them again.