What are the rules of significant figures?

Non-zero digits are always significant. (1.1122 has 5 sig figs.)

Any zeroes between two significant figures are significant. (1.0102 has 5 sig figs.)

Placeholder zeroes are not significant. (0.01122 has 4 sig figs.)

Terminal zeroes are significant. Zeroes both after a decimal point and significant digits. (1.11200 has 6 sig figs.)

Exponential digits in scientific notation are not significant. (1.12 x 10^6 has 3 sig figs.)

When adding or subtracting, follow these steps to find a sig figs answer:

1) Add/Subtract numbers regularly.

2) Determine which measurement has the least decimal places.

3) Round final answer to the same number of decimal places.

When multiplying or dividing, follow these:

1) Count the number of sig figs in the numbers you are multiplying/dividing.

2) Multiply/Divide regularly.

3) Round final answer to the same number of sig figs as the measurement with the fewest sig figs.