Explanation:
For multiplication or division, the rule is to count the number of significant figures in each number being multiplied or divided and then limit the significant figures in the answer to the lowest count.
a. 20.0 meters x 0012.65 meters
The numbers are;
20.0 (3 s.f) and 12.65 (4 s.f)
The multiplication gives; 253
Since 253 is already in 3 s.f, that's the answer.
b. 002.5 × 103 meters + 3.50 × 102 meters
The numbers are;
002.5 (2 s.f), 103 (3 s.f), 3.50 (3 s.f) and 102 (3 s.f)
002.5 × 103 = 257.5 = 260 (2 s.f)
3.50 × 102 = 357 = 360 (2 s.f)
260 + 360 = 620
