Rounding Measurements with Significant Digits

Front

What are significant digits?

Back

Significant digits (or significant figures) are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion.

Front

How do you determine the number of significant digits in a measurement?

Back

To determine the number of significant digits, count all non-zero digits, any zeros between them, and trailing zeros in a decimal number. Leading zeros are not counted.

Front

What is the rule for rounding when adding or subtracting measurements?

Back

When adding or subtracting, the result should be rounded to the least number of decimal places of any number in the operation.

Front

What is the rule for rounding when multiplying or dividing measurements?

Back

When multiplying or dividing, the result should be rounded to the same number of significant digits as the measurement with the least number of significant digits.

Front

Calculate the difference: 78.34 miles - 25.89 miles. What is the rounded result?

Back

52.45 mi

Front

Calculate the total: 23.5 psi + 19.78 psi. What is the rounded result?

Back

43.3 psi

Front

Calculate the difference: 15.489 seconds - 3.0 seconds. What is the rounded result?

Back

18.5 sec

Front

Calculate the total: 2.5 inches + 3.75 inches + 1.8 inches. What is the rounded result?

Back

8.1 in

Front

What is the result of multiplying 2 1/4 feet by 2.2 feet?

Back

5.0 ft²

Front

What is the significance of trailing zeros in a decimal number?

Back

Trailing zeros in a decimal number are significant because they indicate precision. For example, 2.300 has four significant digits.