Rules for Using Significant Figures in Mathematical Operations

Round up whenever the digit following the last significant figure is a 6,7,8,9 or a 5 with any nonzero digit at any place after it. For example, 22.49 becomes 22.5. For example, 54.7511 round to the tenths place becomes 54.8. If the digit following the last significant figure is a 5 with either zeros or nothing after it, round to the even number. ................
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