Decimal Operations: Add, Subtract, Multiply, Divide — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. In the number 4.738, the digit 7 is in the tenths place.
Decimal place values from the decimal point: tenths (1st), hundredths (2nd), thousandths (3rd). In 4.738, the digit 7 is 1st after the decimal → tenths place.
2. The decimal 0.025 is read as twenty-five thousandths.
0.025 has digits to the thousandths place. The last digit (5) is in the thousandths place, so we read the entire decimal number as 'twenty-five thousandths.'
3. 6.400 written without unnecessary trailing zeros is 6.4.
Trailing zeros after the last nonzero decimal digit do not change the value. 6.400 = 6.40 = 6.4.
4. The value of the digit 9 in 3.091 is 0.09.
In 3.091: 0 is in tenths (0.0), 9 is in hundredths (0.09), 1 is in thousandths. The digit 9 has a value of 9 hundredths = 0.09.
5. 0.5 is equivalent to 50 hundredths.
0.5 = 5 tenths = 50 hundredths. Multiplying by 10/10: 0.5 = 0.50 = 50 hundredths.
6. In 12.306, the digit 3 has a value of 3 tenths.
In 12.306: the digit after the decimal point (3) is in the tenths place. Its value is 3 tenths = 0.3.
7. Writing 8 + 0.2 + 0.05 in standard form gives 8.25.
8 = ones, 0.2 = tenths, 0.05 = hundredths. Standard form: 8.25.
8. The number 0.750 rounded to the nearest tenth is 0.8.
Rounding 0.750 to the nearest tenth: the hundredths digit is 5, so round up the tenths digit from 7 to 8. Answer: 0.8.
9. One thousandth written as a decimal is 0.001.
Thousandths is the third decimal place. 1/1000 = 0.001.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
0.3 + 0.45
→ 0.75
0.46
1.0 − 0.62
→ 0.38
0.38
4 tenths + 6 hundredths
→ 0.46
0.25
2 × 0.125
→ 0.25
0.75
0.3+0.45=0.75; 1.0−0.62=0.38; 4 tenths + 6 hundredths=0.40+0.06=0.46; 2×0.125=0.25.