The last one because it take more time
800 m times the meter to cm conversion factor would be:
100 cm
(800 m) * ---------- = 80000 cm
1 m
So 800 m 35 cm would be 80035 cm.
Likewise, 154 m would be 15400 cm, and so 154 m 49 cm would be
15449 cm.
Subtracting 15449 cm from 80035 cm, we get 64586 cm.
This is one way in which to do this problem.
We could convert 64586 cm back to meters: 645 m 86 cm
1,089 squared = (1,089) x (1,089) = 1,185,921 .
But 1,089 itself is a perfect square.
(33) x (33) = 1,089
The answer can be 4
4 - 3 = 1