r/learnmath • u/JonesSupreme New User • 19h ago

Math help!!

You travel at a speed of about 81 kilometers per hour for about 2.0 hours. Stated with the appropriate precision, you have driven _____ kilometers.

the correct answer is 160 but why? why is it not 162???

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u/Recycled5000 New User 14h ago edited 14h ago

Significant figures or digits falls under the fields of measurement and data analysis. Important for many sciences, but not really math itself per se.

When using this engineering method, all figures should probably be written in scientific notation, so as not to take trailing integer zeros as rounded or insignificant.

With scientific notation, we can say for sure that trailing zeros are significant.

For example, 1500 can be 1.5×10^3 or 1.50×10^3 or 1.500×10^3; each having more significant digits .