Question

Your answer should have the same number of significant figures as the starting measurement.

Answer 1

0.0510 cm = 0.510mm just to be clear the answer is B.

Answer 2

cm and mm are both units used to measure length

the starting measurement is 0.0510 cm

The number of significant figures are the number of digits starting from the first non zero digit from left to right

in 0.0510 the first non zero digit from the left is 5

then there are 3 significant figures. The last zero too is significant

1 cm is equivalent to 10 mm

therefore 0.0510 cm = 10 mm/cm x 0.0510 cm = 0.510 mm

the answer 0.510 too has 3 significant figures, same as 0.0510 cm

correct answer is B, 0.510 mm