به انگلیسی

Rounding decimals and significant figures

Mathematics · Number Representation & Place Value · ages 11-13

Name ______________________ Date ____________

Round 0.0674 to 2 decimal places.
Answer: ______________
The rounded value is written as 6.30. How many decimal places does this show?
Answer: ______________
Round 7.253 to 1 decimal place.
- 7.2
- 7.3
- 7.25
To round 3.86 to 1 decimal place, you look at the hundredths digit to decide.
Circle one: True False
Round 0.00996 to 2 significant figures. Type the rounded number.
Answer: ______________
True or false: 5.76 and 5.84 both round to 5.8 when rounded to the nearest tenth.
Circle one: True False
Round 0.0387 to 2 significant figures.
- 0.04
- 0.039
- 0.038
Nia gets 8.5 by rounding 8.449 to 2 decimal places and then to 1 decimal place. What is 8.449 rounded directly to 1 decimal place?
Answer: ______________
Which pair rounds 0.04786 to 2 decimal places and to 2 significant figures, in that order?
- 0.048 and 0.05
- 0.04 and 0.047
- 0.05 and 0.048
- 0.05 and 0.047
Amir rounds 6.995 to 2 decimal places and writes 6.99. Is he correct?
- No, it should round up to 7.00
- No, it should round up to 7.10
- Yes, that is correct

Answer key

For grown-ups. Fold this page away before handing over the rest.

0.07 · Keep the tenths digit 0 and hundredths digit 6. The next digit is 7, so the hundredths digit becomes 7. The result is 0.07.
2 · Both digits after the decimal point count, including the ending zero. The digits 3 and 0 show 2 decimal places.
7.3 · The digit after the tenths place is 5, so the 2 rounds up to 3. The answer is 7.3.
True · The hundredths digit, 6, tells you whether the tenths digit rounds up or stays the same.
0.01 · Keep the two 9s and check 6. Rounding up carries into a new place. Write 0.010 to show 2 significant figures; its numerical value is 0.01.
True · Two different decimals can land on the same rounded value if they're both close enough to it.
0.039 · The first two significant figures are 3 and 8. The next digit, 7, rounds the 8 up to 9, giving 0.039.
8.4 · Direct rounding checks the hundredths digit of the original number. It is 4, so the tenths digit stays 4 and the result is 8.4.
0.05 and 0.048 · For 2 decimal places, check the 7 and get 0.05. For 2 significant figures, keep 4 and 7, check 8 and get 0.048.
No, it should round up to 7.00 · The thousandths digit is 5, so add one hundredth to 6.99. Since 6.99 + 0.01 = 7.00, the result is 7.00. Both zeros show the requested 2 decimal places.