Multi-Digit Multiplication — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A theater has 26 rows with 34 seats in each row. How many seats are in the theater?
A) 784
B) 864
C) 884
D) 904
26×34: 26×4=104; 26×30=780; 104+780=884.
2. Which is the best estimate for 78 × 43?
A) 2,400
B) 3,200
C) 3,600
D) 4,000
Round to 80×40=3,200. (Actual: 78×43=3,354.)
3. What is 1,476 × 5?
A) 7,280
B) 7,380
C) 7,480
D) 7,580
1,476×5: 6×5=30 (write 0, carry 3); 7×5+3=38 (write 8, carry 3); 4×5+3=23 (write 3, carry 2); 1×5+2=7. Product = 7,380.
4. A warehouse ships 48 boxes per truck. Each box holds 36 items. How many items are on one full truck?
A) 1,628
B) 1,728
C) 1,828
D) 1,928
48×36: 48×6=288; 48×30=1,440; 288+1,440=1,728.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 2,345 × 7 = 16,415
5×7=35 (write 5, carry 3); 4×7+3=31 (write 1, carry 3); 3×7+3=24 (write 4, carry 2); 2×7+2=16. Product = 16,415.
2. 65 × 43 = 2,795
65×3=195; 65×40=2,600; 195+2,600=2,795.
3. A library has 1,358 books on each of 6 floors. The library has 8,148 books in all.
1,358×6: 8×6=48 (write 8, carry 4); 5×6+4=34 (write 4, carry 3); 3×6+3=21 (write 1, carry 2); 1×6+2=8. Product = 8,148.
4. Estimate 3,215 × 4 by rounding: 3,200 × 4 = 12,800
3,200×4=12,800. (Actual: 3,215×4=12,860.)
5. 87 × 56 = 4,872
87×6=522; 87×50=4,350; 522+4,350=4,872.