➕ Topic Summary
Two-digit by two-digit multiplication involves multiplying a two-digit number by another two-digit number. This is typically done using the standard algorithm, which involves breaking down the problem into smaller, manageable steps. First, multiply the ones digit of the bottom number by the top number. Then, multiply the tens digit of the bottom number by the top number, remembering to add a zero as a placeholder. Finally, add the two results together to get the final answer. Let's practice!
🔤 Part A: Vocabulary
- 🔍 Product: The answer you get after multiplying two or more numbers.
- ➕ Factor: Numbers you multiply together to get a product.
- 0️⃣ Placeholder: A digit, like zero, used to hold a place value in a number.
- ➗ Algorithm: A step-by-step procedure for solving a mathematical problem.
- 🔢 Partial Product: The result of multiplying one digit of a factor by the other factor.
✍️ Part B: Fill in the Blanks
When multiplying 2-digit numbers, we first multiply the top number by the _____ digit of the bottom number. Then, we multiply by the _____ digit and add a _____ as a placeholder. These individual multiplications create _____ _____, which we then _____ together to get the final product.
🤔 Part C: Critical Thinking
Explain in your own words why it is important to use a placeholder (zero) when multiplying the tens digit in 2-digit by 2-digit multiplication.
➗ Practice Worksheet: Multiply these 2-Digit Numbers!
| 1. $23 \times 12 = $ |
2. $35 \times 21 = $ |
| 3. $41 \times 15 = $ |
4. $52 \times 24 = $ |
| 5. $68 \times 11 = $ |
6. $73 \times 32 = $ |
| 7. $84 \times 13 = $ |
8. $95 \times 42 = $ |