Formative Assessment: Significant Figures

• 5

• 3

• 2

• 4

Answer explanation

The number 0.00340 has three significant figures: the '3' and '4' are significant, and the trailing '0' after the decimal point is also significant. Leading zeros are not counted.

• 2

• 4

• 3

• 1

Answer explanation

The number 1300 has 4 significant figures because the trailing zeros are significant in a number with a decimal point. Therefore, the correct answer is 4.

Which of the following measurements is expressed with 3 significant figures?

Answer explanation

The measurement 0.0403 has 3 significant figures: the leading zeros are not counted, while the digits 4, 0, and 3 are significant. In contrast, 4.00 has 3 significant figures, but 0.040 and 40.3 do not meet the criteria.

• 3

• 2

• 4

• 1

Answer explanation

When multiplying, the result should have the same number of significant figures as the factor with the least significant figures. Here, 2.3 has 2 significant figures, while 4.56 has 3. Therefore, the answer should have 2 significant figures.

Answer explanation

To add 432.1 and 23.04, the result is 455.14. However, the number with the least decimal places is 432.1 (1 decimal place), so the answer should be rounded to 455.1, which is the correct choice.

Answer explanation

The number 0.0040 has three significant figures (the zeros are not leading but the last zero counts). The number 0.040 also has three significant figures, making it the correct choice.

• 3

• 2

• 1

• 4

Answer explanation

When dividing, the result should have the same number of significant figures as the number with the least significant figures. Here, 78.0 has 3 significant figures, and 2.0 has 2 significant figures. Thus, the answer should have 2 significant figures.

• 5

• 2

• 3

• 4

Answer explanation

The number 10,200 has 5 significant figures because the last zero is significant, indicating precision in the measurement. Therefore, the correct answer is 5.

Which measurement is expressed with the greatest number of significant figures?

Answer explanation

The measurement 3.000 has four significant figures, which is the highest among the options. The other measurements have fewer significant figures: 0.00300 has three, 0.0300 has three, and 30.0 has three.

• 2

• 3

• 1

• 4

Answer explanation

When adding numbers, the result should have the same number of decimal places as the measurement with the least decimal places. Here, 0.040 has 2 decimal places, so the answer should also have 2 significant figures.