A measured value of 35m is being multiplied by the countable number 3 (say you went 3 times around a track that was 35m long). What’s the correct number of sigfigs in the answer?

**Method 1**:

35 m x 3 = 105m = 110m

By significant digits rules of multiplication, this would be 110m. (The 35m has 2 sigfigs and 3 has infinite because it is a countable number)

**Method 2**:

35m + 35m + 35m = 105m

By significant digits rules of addition, this would be 105m (All numbers are significant to unit place)

Am I missing something? I can’t imagine the precision of your answer being increased by your choice of adding the number 3 times instead of multiplying by 3.

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