How far does light travel in 65.1 millionths of a second?

d=v x t = 3.0x108 m/s x 6.51x10-5 s

Multiply the mantissas (the numbers before the ‘x’)

19.53 x 108 x 10-5 m/s s

Add the exponents (the numbers above the 10)

19.53 x 103 m/s s

Shift the decimal to the first place by adding or subtracting from the exponent.

1.953 x 104 m/s s

Round to the minimum number of significant digits in the original numbers.

2.0 x 104 m/s s

Cancel units to get the correct units

2.0 x 104 m = 20,000 meters = 12 miles

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