ffirs.indd

Squaring Numbers Ending in 5 229
Test you rself
Now try these for yourself. Don’t write anything—do them
all in your head.
a) 35^2
b) 85^2
c) 115^2
d) 985^2
The answers are:
a) 1,225 b) 7,225 c) 13,225 d) 970,225
For more strategies about squaring numbers (and fi nding square
roots), you should read my book Speed Mathematics.
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