Decimal Addition and Subtraction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 0.45 + 0.5 = 0.95 (rewrite 0.5 as 0.50)
Grade 4 students write 0.5 as 0.50, then add hundredths and tenths to get 0.95.
2. 0.8 - 0.25 = 0.55
Grade 4 learners annex a zero, making 0.80 - 0.25 = 0.55 by subtracting columns.
3. Write 5/10 as a decimal: 0.5
Grade 4 students recognize 5/10 as 5 tenths, written 0.5.
4. Write 64/100 as a decimal: 0.64
Grade 4 learners write 64/100 as 0.64 because 6 is in the tenths place and 4 is in the hundredths place.
5. 0.27 + 0.3 = 0.57
Grade 4 students rewrite 0.3 as 0.30, then add to 0.27 to get 0.57.
6. 0.9 = 0.90 (annex a zero)
Grade 4 learners write 0.9 as 0.90 because 9 tenths equals 90 hundredths.
7. 0.75 - 0.5 = 0.25
Grade 4 students annex a zero, making 0.50, then subtract from 0.75 to get 0.25.
8. 0.6 + 0.15 = 0.75
Grade 4 learners rewrite 0.6 as 0.60, then add hundredths and tenths to get 0.75.
9. Write 0.42 as a fraction with denominator 100: 42/100
Grade 4 students recognize 0.42 as 42 hundredths, equal to 42/100.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
3/10 as decimal
→ 0.3
0.3
27/100 as decimal
→ 0.27
0.27
0.5 + 0.25
→ 0.75
0.75
0.8 - 0.55
→ 0.25
0.25
Grade 4 students connect fractions like 3/10 to 0.3 and 27/100 to 0.27, then practice decimal sums and differences.