← Back to the Decimal Operations worksheet
Last updated: October 22, 2026 · Written by the Math Made Easy math teachers
Every problem has a full worked solution with the final answer in bold. Look at how the decimal points are aligned or counted, and compare each answer with a quick estimate.
Standards: 6.NS.B.3 · Level: Grade 6
Problem 1 Adding Decimals
Write 12.90 under 3.46 with the points aligned: 3.46 + 12.90 = 16.36.
Answer: 16.36.
Problem 2 Subtracting from a Whole Number
Write 20 as 20.00. Then 20.00 − 7.35 = 12.65.
Check: 12.65 + 7.35 = 20.
Answer: 12.65.
Problem 3 Adding Money
4.75 + 12.40 = 17.15, and 17.15 + 0.99 = 18.14.
Answer: $18.14.
Problem 4 Subtracting with Zeros
Write 2.76 as 2.760. Then 8.004 − 2.760 = 5.244.
Check: 5.244 + 2.760 = 8.004.
Answer: 5.244.
Problem 5 Aligning Decimals
Hundredths: 0 + 8 + 0 = 8. Tenths: 6 + 7 + 0 = 13, write 3 carry 1. Ones: 5 + 0 + 4 + 1 = 10, write 0 carry 1. Tens: 1 + 1 = 2.
Answer: 20.38.
Problem 6 Decimal Times Whole Number
(a) 64 × 7 = 448; one decimal place gives 44.8.
(b) 35 × 12 = 420; two decimal places give 4.20 = 4.2.
Answer: (a) 44.8; (b) 4.2.
Problem 7 Decimal Times Decimal
(a) 36 × 7 = 252, two places: 2.52.
(b) 8 × 9 = 72, three places: 0.072.
(c) 125 × 4 = 500, three places: 0.500 = 0.5.
Answer: (a) 2.52; (b) 0.072; (c) 0.5.
Problem 8 Placing the Point
(a) 1 + 1 = 2 decimal places: 10.81.
(b) 2 + 2 = 4 places: 0.1081.
(c) 0 + 3 = 3 places: 1.081.
Answer: (a) 10.81; (b) 0.1081; (c) 1.081.
Problem 9 Dividing by a Whole Number
(a) 17.5 ÷ 5 = 3.5.
(b) 9.36 ÷ 12 = 0.78, since 12 × 0.78 = 9.36.
Answer: (a) 3.5; (b) 0.78.
Problem 10 Quotients That Keep Going
(a) 7.000 ÷ 8 = 0.875.
(b) 9.0000 ÷ 16 = 0.5625.
Check: 8 × 0.875 = 7 and 16 × 0.5625 = 9.
Answer: (a) 0.875; (b) 0.5625.
Problem 11 Dividing by a Decimal
(a) Multiply by 100: 840 ÷ 7 = 120.
(b) Multiply by 10: 45.5 ÷ 13 = 3.5.
(c) Multiply by 100: 96 ÷ 8 = 12.
Answer: (a) 120; (b) 3.5; (c) 12.
Problem 12 Garden Bed Area
46 × 25 = 1,150. The factors have 2 decimal places, so the area is 11.50 = 11.5.
Answer: 11.5 square feet.
Problem 13 Estimate, Then Multiply
(a) 18.7 ≈ 19 and 4.9 ≈ 5, so 19 × 5 = 95.
(b) 187 × 49 = 9,163 and two decimal places give 91.63.
Answer: (a) about 95; (b) 91.63.
Problem 14 Order of Operations
Multiply first: 3.2 × 2.5 = 8. Then 12.5 − 8 = 4.5.
Answer: 4.5.
Problem 15 Filling the Tank
Gas: 11.4 × 3.85 = 43.89.
Change: 50 − 43.89 = 6.11.
Answer: $43.89 for gas and $6.11 in change.
Problem 16 Grocery Receipt
3.89 + 2.75 = 6.64; 6.64 + 1.95 = 8.59; 8.59 + 5.49 = 14.08.
Change: 20 − 14.08 = 5.92.
Answer: total $14.08, change $5.92.
Problem 17 Jogging Speed
(a) 3.6 ÷ 0.75 = 360 ÷ 75 = 4.8.
(b) 4.8 × 1.5 = 7.2.
Answer: (a) 4.8 miles per hour; (b) 7.2 miles.
Problem 18 Cutting Trim
12.6 ÷ 0.45 = 1,260 ÷ 45 = 28.
Check: 0.45 × 28 = 12.6.
Answer: 28 pieces.
Problem 19 Taxi Fares
(a) 2.50 × 8.4 = 21, and 3.50 + 21 = 24.50.
(b) 34.50 − 3.50 = 31, and 31 ÷ 2.5 = 12.4.
Answer: (a) $24.50; (b) 12.4 miles.
Problem 20 Relay Times
(a) 12.45 + 11.9 + 13.05 + 12.6 = 50.
(b) 50 ÷ 4 = 12.5.
(c) 13.05 − 11.9 = 1.15.
Answer: (a) 50 seconds; (b) 12.5 seconds; (c) 1.15 seconds.