Multiply two-digit multiples of 10 by two-digit multiples of 10 with the area model. Practice — Grade 4 math

Lesson 3: Multiply two-digit multiples of 10 by two-digit multiples of 10 with the area model. — Practice Questions

1. Use decomposition to multiply the numbers. What is the product of $40 \times 20$? $40 \times 20 = \_\_\_$
2. Which expression shows the correct way to decompose and regroup the factors to solve $70 \times 50$?
- A. (7 × 5) × (10 × 10)
- B. (7 × 10) × 5
- C. (7 + 5) × 100
- D. 7 × 5 × 10
3. A farmer plants 60 rows of corn with 30 corn plants in each row. How many corn plants are there in total? $60 \times 30 = \_\_\_$
4. Calculate the product of $80$ and $50$ by decomposing the factors. $80 \times 50 = \_\_\_$
5. The expression $(4 \times 3) \times (10 \times 10)$ is the regrouped form of which original multiplication problem?
- A. 40 × 30
- B. 4 × 30
- C. 40 × 3
- D. 40 + 30
6. What is the result of multiplying 7 tens by 2 tens? $70 \times 20 = \_\_\_$
7. Which of the following multiplication expressions has the same value as $30 \times 80$?
- A. 40 × 50
- B. 60 × 40
- C. 70 × 30
- D. 20 × 90
8. Calculate the product of $70$ and $20$. The answer is ___.
9. Which expression correctly uses decomposition and regrouping to solve $50 \times 80$?
- A. $(5 \times 8) \times (10 \times 10)$
- B. $(5 + 8) \times 100$
- C. $(5 \times 10) + (8 \times 10)$
- D. $5 \times 8 \times 10$
10. A farmer plants 40 rows of corn with 60 seeds in each row. The total number of seeds planted is ___.