Question

1. round each of the following numbers to three significant figures.

a) 342.79513
b) 9,845.8749
c) 0.000045389
d) 2.45555567
e) 76.89
f) 56.9971

Explanation:

Step1: Identify significant - figure rules

Non - zero digits are significant. Zeros between non - zero digits are significant. Leading zeros are not significant. Trailing zeros in a number with a decimal point are significant.

Step2: Round 342.79513

The fourth significant figure is 7. Since 7≥5, we round up. So 342.79513 rounds to 343.

Step3: Round 9,845.8749

The fourth significant figure is 5. Since 5≥5, we round up. So 9,845.8749 rounds to 9,850.

Step4: Round 0.000045389

The first significant figure is 4. The fourth significant figure is 8. Since 8≥5, we round up. So 0.000045389 rounds to 0.0000454.

Step5: Round 2.45555567

The fourth significant figure is 5. Since 5≥5, we round up. So 2.45555567 rounds to 2.46.

Step6: Round 76.89

The fourth significant figure is 9. Since 9≥5, we round up. So 76.89 rounds to 76.9.

Step7: Round 56.9971

The fourth significant figure is 9. Since 9≥5, we round up. So 56.9971 rounds to 57.0.

Answer:

a) 343
b) 9,850
c) 0.0000454
d) 2.46
e) 76.9
f) 57.0