Multi-Digit Multiplication — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 34 × 21 = 714
34×1=34; 34×20=680; 34+680=714.
2. 56 × 13 = 728
56×3=168; 56×10=560; 168+560=728.
3. 45 × 27 = 1,215
45×7=315; 45×20=900; 315+900=1,215.
4. 82 × 36 = 2,952
82×6=492; 82×30=2,460; 492+2,460=2,952.
5. To estimate 48 × 31, round to 50 × 30 = 1,500
50×30=1,500. (Actual: 48×31=1,488.)
6. 63 × 42 = 2,646
63×2=126; 63×40=2,520; 126+2,520=2,646.
7. The first partial product of 57 × 23 is 57 × 3 = 171
57×3: 7×3=21 (write 1 carry 2); 5×3+2=17. First partial product = 171.
8. The second partial product of 57 × 23 is 57 × 20 = 1,140
57×2=114; then append one zero for the tens position: 1,140.
9. 29 × 15 = 435
29×5=145; 29×10=290; 145+290=435.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
37 × 22
→ 814
954
64 × 15
→ 960
1,426
53 × 18
→ 954
814
46 × 31
→ 1,426
960
37×22=814; 64×15=960; 53×18=954; 46×31=1,426.