Exercise: 3-F
Q1: Round off each of the following to the nearest whole number:
i. 87.46
The decimal part is 0.46, which is less than 0.5, so we round down.
Answer: 87
ii. 65.83
The decimal part is 0.83, which is greater than 0.5, so we round up.
Answer: 66
iii. 71.54
The decimal part is 0.54, which is greater than 0.5, so we round up.
Answer: 72
iv. 98.5
The decimal part is exactly 0.5, so we round up.
Answer: 99
v. 60.29
The decimal part is 0.29, which is less than 0.5, so we round down.
Answer: 60
Q2: Round off:
i. 6.342, correct to 2 decimal places
The third decimal place is 2, which is less than 5, so we round down.
Answer: 6.34
ii. 8.1347, correct to 3 decimal places
The fourth decimal place is 7, which is greater than 5, so we round up.
Answer: 8.135
iii. 0.845, correct to 2 decimal places
The third decimal place is 5, which is 5 or greater, so we round up.
Answer: 0.85
iv. 1.732, correct to 1 decimal place
The second decimal place is 7, which is greater than 5, so we round up.
Answer: 1.7
v. 9.638, correct to 2 decimal places
The third decimal place is 8, which is greater than 5, so we round up.
Answer: 9.64
vi. 0.047, correct to 2 decimal places
The third decimal place is 7, which is greater than 5, so we round up.
Answer: 0.05
Q3: Write the value of:
i. 7.451 to the nearest hundredths
The third decimal place is 1, which is less than 5, so we round down.
Answer: 7.45
ii. 3.157 to the nearest tenths
The second decimal place is 5, which is greater than 5, so we round up.
Answer: 3.2
iii. 0.6428 to the nearest thousandths
The fourth decimal place is 8, which is greater than 5, so we round up.
Answer: 0.643
iv. 0.061 to the nearest tenths
The second decimal place is 6, which is greater than 5, so we round up.
Answer: 0.1
v. 0.136 to the nearest hundredths
The third decimal place is 6, which is greater than 5, so we round up.
Answer: 0.14
Q4: Express \(\frac{6}{7}\) as a decimal, correct to 2 decimal places.
First, we divide \( 6 \div 7 \).
Performing the division gives us: 0.8571…
Now, rounding it off to 2 decimal places, the third decimal place is 7, which is greater than 5, so we round up.
Answer: 0.86
