Question

learning significant figures
circle the numbers that have a specific number of significant figures.

1. circle the numbers that have 3 significant figures.

12340 700 0.0650 9021 0.00780

1. circle the numbers that have 4 significant figures.

1056 0.02005 145 60230 0.000760

1. circle the numbers that have 2 significant figures.

840 0.090 1005 0.0087 56000

1. circle the numbers that have 1 significant figures.

0.004 9000 43 1200 0.0009

1. circle the numbers that have 2 significant figures.

0.145 620 307 0.0093 9700

1. circle the numbers that have 3 significant figures.

0.0342 670 21000 0.00450 8.60

Explanation:

Step1: Recall significant - figure rules

Non - zero digits are always significant. Zeros between non - zero digits are significant. Leading zeros (zeros before the first non - zero digit) are not significant. Trailing zeros (zeros after the last non - zero digit) are significant only if the number contains a decimal point.

Step2: Analyze numbers for 3 significant figures in 1)

• 12340 has 5 significant figures.
• 700 has 1 significant figure (if no decimal point).
• 0.0650 has 3 significant figures (the leading zeros are not significant, and the trailing zero is significant as there is a decimal point).
• 9021 has 4 significant figures.
• 0.00780 has 3 significant figures (leading zeros are not significant, trailing zero is significant as there is a decimal point).

Step3: Analyze numbers for 4 significant figures in 2)

• 1056 has 4 significant figures.
• 0.02005 has 4 significant figures (leading zeros are not significant, zeros between non - zero digits are significant).
• 145 has 3 significant figures.
• 60230 has 5 significant figures (if no decimal point).
• 0.000760 has 3 significant figures.

Step4: Analyze numbers for 2 significant figures in 3)

• 840 has 2 significant figures (if no decimal point).
• 0.090 has 2 significant figures (leading zeros are not significant).
• 1005 has 4 significant figures.
• 0.0087 has 2 significant figures (leading zeros are not significant).
• 56000 has 2 significant figures (if no decimal point).

Step5: Analyze numbers for 1 significant figure in 4)

• 0.004 has 1 significant figure (leading zeros are not significant).
• 9000 has 1 significant figure (if no decimal point).
• 43 has 2 significant figures.
• 1200 has 2 significant figures (if no decimal point).
• 0.0009 has 1 significant figure (leading zeros are not significant).

Step6: Analyze numbers for 2 significant figures in 5)

• 0.145 has 3 significant figures.
• 620 has 2 significant figures (if no decimal point).
• 307 has 3 significant figures.
• 0.0093 has 2 significant figures (leading zeros are not significant).
• 9700 has 2 significant figures (if no decimal point).

Step7: Analyze numbers for 3 significant figures in 6)

• 0.0342 has 3 significant figures (leading zeros are not significant).
• 670 has 2 significant figures (if no decimal point).
• 21000 has 2 significant figures (if no decimal point).
• 0.00450 has 3 significant figures (leading zeros are not significant, trailing zero is significant as there is a decimal point).
• 8.60 has 3 significant figures (trailing zero is significant as there is a decimal point).

Answer:

1. 0.0650, 0.00780
2. 1056, 0.02005
3. 840, 0.090, 0.0087, 56000
4. 0.004, 9000, 0.0009
5. 620, 0.0093, 9700
6. 0.0342, 0.00450, 8.60