Significant Figures Quiz

Identify the number of significant figures in the number 0.00456.

• 2

• 3

• 4

• 5

Answer explanation

The number 0.00456 has 3 significant figures because all non-zero digits are considered significant, and zeros between non-zero digits are also significant.

Round the number 12345 to 3 significant figures.

• 12300

• 12400

• 12350

• 12300

Answer explanation

To round 12345 to 3 significant figures, we look at the first three digits from the left. Since the fourth digit is 5 or more, we round up the third digit to get 12300.

Round the number 0.007891 to 2 significant figures.

• 0.0078

• 0.0079

• 0.0080

• 0.00789

Answer explanation

To round 0.007891 to 2 significant figures, we look at the first two non-zero digits after the decimal point, which are 7 and 8. Since 8 is greater than 5, we round up the 7 to get 0.0079.

Which of the following numbers has 4 significant figures?

• 0.00456

• 1234

• 1000

• 0.04560

Answer explanation

The number 0.04560 has 4 significant figures because all non-zero digits are significant, and the zeros between the decimal point and the last non-zero digit are also significant.

Round the number 98765 to 4 significant figures.

• 98760

• 98770

• 9876

• 9877

Answer explanation

To round 98765 to 4 significant figures, we look at the digit after the 4th significant figure, which is 6. Since it is less than 5, we keep the 4 significant figures unchanged, resulting in 98760 as the rounded number.

Round the number 0.0004567 to 3 significant figures.

• 0.000457

• 0.000456

• 0.00046

• 0.00045

Answer explanation

To round 0.0004567 to 3 significant figures, we look at the first 3 non-zero digits which are 4, 5, and 6. Since the next digit is 7, we round up the last digit to get 0.000457.

Add the numbers 12.34 and 0.567 and round the result to 3 significant figures.

• 12.9

• 12.91

• 12.907

• 12.8

Answer explanation

To add 12.34 and 0.567, we get 12.907. Rounding to 3 significant figures gives 12.91, which is the correct answer.

Multiply the numbers 4.56 and 0.789 and round the result to 2 significant figures.

• 3.6

• 3.60

• 3.59

Answer explanation

To multiply 4.56 and 0.789, we get 3.5964. Rounding to 2 significant figures gives 3.6, making it the correct choice.

Identify the number of significant figures in the number 100.0.

• 1

• 2

• 3

• 4

Answer explanation

The number 100.0 has 4 significant figures because zeros between non-zero digits and after a decimal point are considered significant.

Round the number 0.00012345 to 2 significant figures.

• 0.00012

• 0.00013

• 0.000123

• 0.000124

Answer explanation

To round 0.00012345 to 2 significant figures, we look at the third digit which is 3. Since it is greater than 5, we round up the second digit to get 0.00013.