📚 Topic Summary
Multiplying a 1-digit number by a multi-digit number with regrouping involves breaking down the problem into smaller, manageable steps. First, multiply the 1-digit number by each digit of the multi-digit number, starting from the rightmost digit. If the result is greater than 9, you'll need to regroup, carrying the tens digit to the next column. Continue this process for each digit, adding any regrouped numbers as you go. This method ensures accurate multiplication of larger numbers.
Regrouping, also known as carrying over, is a crucial step when the product of two digits exceeds 9. The tens digit of the product is carried over to the next column on the left, while the ones digit remains in the current column. This ensures that each place value column contains only a single digit, simplifying the overall calculation and preventing errors in the final answer.
🔤 Part A: Vocabulary
Match the following terms with their definitions:
- Product
- Regrouping
- Factor
- Multiplication
- Digit
Definitions:
- A symbol used to represent a number (0-9).
- The process of combining groups of equal sizes.
- A number that is multiplied by another number.
- The answer to a multiplication problem.
- The process of carrying over to the next place value when multiplying.
✍️ Part B: Fill in the Blanks
Complete the following paragraph with the correct words:
When multiplying $7 \times 25$, we first multiply $7$ by $5$, which equals _____. We write down the _____ and carry over the _____. Next, we multiply $7$ by $2$, which equals _____. We add the carried over _____ to get _____. Therefore, $7 \times 25 = $ _____.
🤔 Part C: Critical Thinking
Explain in your own words why regrouping is important when multiplying multi-digit numbers.