Following all significant figure rules use your calculator to solve: 10.26 + 645.9. enter your answer using scientific notation as well

Answer 1

Rules to know for significant figures:

1. Non-zero digits are always significant. (22 has 2 significant figures)
2. Zeros between significant digits are significant. (202 has 3 significant figures)
3. Zeros after significant digits are only significant after a decimal point (200.0 has 4 significant figures but 0.002 only has 1)

Rules to know when adding and subtracting with significant figures:

1. Look at significant digits after the decimal point. Add/subtract normally and round your answer to the least number of digits after the decimal point. (43.270+7.1=50.4)

Rules to know when multiplying and dividing with significant figures:

1. Multiply/divide normally, and round to the least number of significant figures in the problem. (10.05x32=320)

Therefore, using the addition rules, we can see that when we add 10.26 (2 sig figs after the decimal) and 645.9 (1 sig fig after the decimal), we should round our answer to 1 sig fig after the decimal. We get that: 10.26+645.9=656.16; rounding to the proper significant figures we see that 656.16 becomes 656.2. Using scientific notation this becomes 6.562x10².