➕ Topic Summary
Multiplying a 2-digit number by a 1-digit number using the standard algorithm involves breaking down the problem into smaller steps. First, multiply the ones digit of the 2-digit number by the 1-digit number. Then, multiply the tens digit of the 2-digit number by the 1-digit number. Remember to carry over when necessary. Finally, add the partial products to find the final answer.
For example, to solve $23 \times 4$, you would multiply $3 \times 4 = 12$. Write down the 2 and carry-over the 1. Then multiply $2 \times 4 = 8$, and add the carry-over 1 to get 9. So, $23 \times 4 = 92$.
🔤 Part A: Vocabulary
Match the term with its definition:
- Term: Product
- Term: Factor
- Term: Algorithm
- Term: Multiply
- Term: Carry-over
- Definition: A step-by-step procedure for solving a problem.
- Definition: To increase a number by a certain factor.
- Definition: The result of multiplication.
- Definition: A number that divides another number evenly.
- Definition: A digit transferred from one column to another during calculation.
Match the numbers and their definitions! Good luck!
✍️ Part B: Fill in the Blanks
When multiplying a 2-digit number by a 1-digit number using the standard algorithm, we first multiply the ______ digit by the 1-digit number. If the result is greater than 9, we ______ over the tens digit. Next, we multiply the ______ digit by the 1-digit number and add the carry-over (if any). Finally, we write down the result to obtain the ______.
🤔 Part C: Critical Thinking
Explain in your own words why it's important to understand the standard algorithm for multiplication, even though calculators are readily available. Provide at least two reasons.