Question

(42.70 + 0.259) / 28.4

I wanted to know, if it 1.510 or 1.51? because it has to be correct sig figs.

Answer 1

Your answer will be 1.51 because my teacher said you always solve for the lowest original number of sig figs in your problem, which in this case would be 3

Answer 2

wait oops xd i forgot rest of problem

it was

(42.70 + 0.259) / 28.4445 >_< sorry about that

Answer 3

I don't understand the <_>.
When you multiply or divide, Lisa is correct; i.e., the answer contains no more significant figures than the least accurate of the values used in the multiplication or division. For example, 24.3 x 0.98774 = 24.0082. Since the 24.3 has the smaller number of s.f., the answer should be rounded to 3 places which would make it 24.0
When the numbers are added or subtracted, the rule is a little different. For example,
24.1 + 0.113 + 0.5 = 24.71300 which will be rounded to the "NEAREST 0.1 SINCE that is the least accurate of the numbers. The answer will be 24.7. Here is a site that may help you.
http://members.aol.com/profchm/sig_fig.html