| Question | Answer |
| When is a zero a significant digit? | Any zeros to the right of a decimal are significant. Ex: 8.00
Any zeros to the right of a non-zero number in a decimal. Ex: 1.80
Any zeros between non-zeros are significant Ex: 3,001 |
| When is zero NOT significant? | Any zero to the left of a whole number is NOT significant. Ex: 2,340,000
Any zero between a decimal and non-zero numbers in a decimal are NOT significant. Ex: 6.007 |
| Are any non-zero number significant or not significant? | Significant |
| What is the rule of rounding to the appropriate significant digit when adding or subtracting? | Round the lowest place value of the LEAST precise number in the problem. EX: 2.3 - 0.623 (Solve and round to the tenths place) = 1.7 |
| What is the rule of rounding to the appropriate significant digit when multiplying or dividing? | Round the same number of significant digits as the LEAST precise number in the problem. EX: 20 ÷ 0.06 (Solve and round to 1 significant digit- ones place) = 1 |
| Determine the number of significant digits:
0.0009 | 1 |
| Determine the number of significant digits:
204.0 | 4 |
| Determine the number of significant digits:
230 | 2 |
| Determine the number of significant digits:
8.2003 | 5 |
| Determine the number of significant digits:
0.003405 | 4 |
| Determine the number of significant digits:
6,001,020 | 6 |
| Determine the number of significant digits:
34,560 | 4 |
| Determine the number of significant digits:
800 | 1 |
| Determine the number of significant digits:
0.0980 | 3 |
| Determine the number of significant digits:
0.80030 | 5 |
| Determine the number of significant digits:
200.04 | 5 |
| Solve the problem by rounding to the correct number of significant digits: 700 + 63.9 | 764 |
| Solve the problem by rounding to the correct number of significant digits: 0.82 x 1.5 | 1.2 |
| Solve the problem by rounding to the correct number of significant digits: 320 x 0.45 | 140 |
| Solve the problem by rounding to the correct number of significant digits: 0.6782 - 0.599 | 0.079 |
| Solve the problem by rounding to the correct number of significant digits: 0.066528 ÷ 0.042 | 1.584 (answer in correct number of significant digits- no rounding needed) |
| Solve the problem by rounding to the correct number of significant digits: 15,399.6 ÷ 1,230 | 12.5 |
| Solve the problem by rounding to the correct number of significant digits: 23,892 + 2,120 | 26,010 (Least precise is 2,120 with the lowest place value of a significant digit in the tens place) |