I have to convert inches to 250 cm.My book states the expression to calculate this as 250 cm x 1in/2.54 cm. I followed through to divide, and got 98.425, which following the rules of significantdigits, would equal 98, right? 250 only has 2 sig digs, it'd have to be 98. But my book says its 98.4. How can this be?

Question

I have to convert inches to 250 cm.My book  states the expression to calculate this as 250 cm x 1in/2.54 cm.  I followed through to divide, and got 98.425, which following the rules of significantdigits, would equal 98, right? 250 only has 2 sig digs, it'd have to be 98.  But my book says its 98.4.  How can this be?

DrBob222 · Answer

I think your book is counting 250 cm as 250. cm. which makes 3 s.f. and that's how they obtained 98.4. You're right, however, that 250, written that way, has only two s.f.