Question

Which of these numbers has five significant numbers?

! ! 20 Points ! !
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A.) 12.0000345
B.) 50.04300
C.) 1.0000
D.) 5

Answer 1

c

Explanation:

A has 9 sig digits. Every digit counts including the 4 zeros, because 3 digits follow them. Even if the 345 were not there, there still are 6 sig digits.

B. Those two trailing zeros mean something. They are guaranteed place holders. This number has 7 sig digs.

D. Depends on who teaches this. 5 without a period at the end means that the number is exactly 5 -- or that's the rule when I was teaching.

The answer is C, believe it or not. Again, those zeros are place holders. They are guaranteed to be accurate. This is a question to look at carefully.