Multi-Digit Multiplication — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A train travels 1,245 miles each trip. How many miles does it travel in 6 trips?
A) 7,270
B) 7,370
C) 7,470
D) 7,570
Multiply 1,245 × 6: 5 × 6 = 30, 4 × 6 = 24 + 3 = 27, 2 × 6 = 12 + 2 = 14, 1 × 6 = 6 + 1 = 7. The train travels 7,470 miles in 6 trips.
2. Which is the best estimate for 86 × 47?
A) 3,600
B) 4,000
C) 4,500
D) 5,400
Round 86 to 90 and 47 to 50, giving 90 × 50 = 4,500, or round to 80 × 50 = 4,000. Since the exact answer is 4,042, the estimate of 4,000 is the closest choice.
3. A stadium has 64 sections with 78 seats in each section. How many seats are in the stadium?
A) 4,892
B) 4,942
C) 4,992
D) 5,042
Multiply 64 × 78: 64 × 8 = 512 and 64 × 70 = 4,480, so 512 + 4,480 = 4,992 seats in the stadium.
4. In the area model for 57 × 36, which four partial products are added together?
A) 50 × 30, 50 × 6, 7 × 30, 7 × 6
B) 57 × 3, 57 × 6, 57 × 30, 57 × 36
C) 50 × 36, 7 × 36, 50 × 6, 7 × 6
D) 57 × 30, 57 × 6, 50 × 7, 30 × 6
The area model splits 57 into 50 + 7 and 36 into 30 + 6, creating four rectangles: 50 × 30 = 1,500, 50 × 6 = 300, 7 × 30 = 210, and 7 × 6 = 42. Their sum is 2,052.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 4,126 × 7 = 28,882
Multiply each digit by 7 from right to left, carrying when needed: 6 × 7 = 42, 2 × 7 = 14 + 4 = 18, 1 × 7 = 7 + 1 = 8, 4 × 7 = 28. The product is 28,882.
2. 83 × 54 = 4,482
Using partial products: 83 × 4 = 332 and 83 × 50 = 4,150. Adding gives 332 + 4,150 = 4,482.
3. A warehouse stores 2,185 items on each of 8 shelves. The warehouse holds 17,480 items.
Multiply 2,185 × 8 to find the total. Working through each digit with carrying gives 17,480 items stored across all 8 shelves.
4. Estimate 4,389 × 5 by rounding: 4,400 × 5 = 22,000
Rounding 4,389 to the nearest hundred gives 4,400. Then 4,400 × 5 = 22,000, which is a quick estimate close to the exact product of 21,945.
5. 76 × 89 = 6,764
Using partial products: 76 × 9 = 684 and 76 × 80 = 6,080. Adding gives 684 + 6,080 = 6,764.