Multi-Digit Multiplication — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
246 × 3 = 638 because 6 × 3 = 18, carry the 1, then 4 × 3 = 12 plus 1 = 13, carry the 1, then 2 × 3 = 6 plus 1 = 7.
Corrected: 246 × 3 = 738 because 6 × 3 = 18, write 8 carry 1, then 4 × 3 = 12 plus 1 = 13, write 3 carry 1, then 2 × 3 = 6 plus 1 = 7.
The corrected sentence is: "246 × 3 = 738 because 6 × 3 = 18, write 8 carry 1, then 4 × 3 = 12 plus 1 = 13, write 3 carry 1, then 2 × 3 = 6 plus 1 = 7.". The original sentence "246 × 3 = 638 because 6 × 3 = 18, carry the 1, then 4 × 3 = 12 plus 1 = 13, carry the 1, then 2 × 3 = 6 plus 1 = 7." contained an error that needed to be fixed.
2. Fix the sentence:
1,523 × 4 = 6,082 because 3 × 4 = 12, carry the 1, then 2 × 4 = 8 plus 1 = 9.
Corrected: 1,523 × 4 = 6,092 because 3 × 4 = 12, write 2 carry 1, then 2 × 4 = 8 plus 1 = 9, write 9.
The corrected sentence is: "1,523 × 4 = 6,092 because 3 × 4 = 12, write 2 carry 1, then 2 × 4 = 8 plus 1 = 9, write 9.". The original sentence "1,523 × 4 = 6,082 because 3 × 4 = 12, carry the 1, then 2 × 4 = 8 plus 1 = 9." contained an error that needed to be fixed.
3. Fix the sentence:
385 × 7 = 2,595 because 5 × 7 = 35, carry the 3, then 8 × 7 = 56 plus 3 = 59, carry the 5, then 3 × 7 = 21 plus 5 = 26.
Corrected: 385 × 7 = 2,695 because 5 × 7 = 35, write 5 carry 3, then 8 × 7 = 56 plus 3 = 59, write 9 carry 5, then 3 × 7 = 21 plus 5 = 26.
The corrected sentence is: "385 × 7 = 2,695 because 5 × 7 = 35, write 5 carry 3, then 8 × 7 = 56 plus 3 = 59, write 9 carry 5, then 3 × 7 = 21 plus 5 = 26.". The original sentence "385 × 7 = 2,595 because 5 × 7 = 35, carry the 3, then 8 × 7 = 56 plus 3 = 59, carry the 5, then 3 × 7 = 21 plus 5 = 26." contained an error that needed to be fixed.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. 312 × 3 = 936
3×3=9, 1×3=3, 3×3=9. Product = 936.
2. 1,204 × 5 = 6,020
4×5=20 (write 0, carry 2); 0×5+2=2; 2×5=10; 1×5=5. Product = 6,020.
3. 463 × 2 = 926
3×2=6; 6×2=12 (write 2, carry 1); 4×2+1=9. Product = 926.
4. To multiply 700 × 8, first find 7 × 8 = 56, then write 2 zeros.
700 has 2 zeros. 7×8=56, then append 2 zeros → 5,600.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain step by step how to multiply 258 × 4.
Sample answer: Multiply 8 × 4 = 32, write 2 carry 3. Then 5 × 4 = 20 plus 3 = 23, write 3 carry 2. Then 2 × 4 = 8 plus 2 = 10. The answer is 1,032.
258 × 4 = 1,032. Multiply digit by digit from right to left, carrying when needed.
2. A farmer plants 215 seeds in each row and has 6 rows. How many seeds does the farmer plant in all?
Sample answer: 215 × 6 = 1,290. The farmer plants 1,290 seeds in all.
215 × 6: 5×6=30 (write 0 carry 3); 1×6+3=9; 2×6=12. Product = 1,290.