➗ Topic Summary
Dividing a 3-digit number by a 2-digit number involves breaking down the problem into smaller, manageable steps. First, estimate how many times the 2-digit number goes into the first two digits (or all three, if needed) of the 3-digit number. Then, multiply the estimated quotient by the 2-digit divisor and subtract the result from the corresponding digits of the dividend. Bring down the next digit and repeat the process until you have a remainder (if any). This process utilizes long division skills and estimation to find the quotient.
For example, let's divide 245 by 15. We first estimate how many times 15 goes into 24. It goes in once, so we write '1' as the first digit of the quotient. Multiply 1 by 15 to get 15, and subtract 15 from 24 to get 9. Bring down the 5 to make 95. Now, estimate how many times 15 goes into 95. It goes in 6 times, so we write '6' as the second digit of the quotient. Multiply 6 by 15 to get 90, and subtract 90 from 95 to get 5. Therefore, 245 divided by 15 is 16 with a remainder of 5.
🧮 Part A: Vocabulary
| Term |
Definition |
| 1. Divisor |
a. The number being divided |
| 2. Dividend |
b. The result of division |
| 3. Quotient |
c. The number that divides the dividend |
| 4. Remainder |
d. The amount left over after division |
| 5. Estimate |
e. An approximate calculation or judgment of the value, number, quantity, or extent of something. |
Match each term with its correct definition:
- 🔍 1 - ___
- 💡 2 - ___
- 📝 3 - ___
- ➗ 4 - ___
- ➕ 5 - ___
✍️ Part B: Fill in the Blanks
When dividing 3-digit numbers by 2-digit numbers, we use a process called ________ ________. The number we are dividing is the ________, and the number we are dividing by is the ________. The answer to the division problem is the ________, and any leftover amount is the ________.
🤔 Part C: Critical Thinking
Explain in your own words how estimation helps in the process of dividing a 3-digit number by a 2-digit number. Give an example to illustrate your explanation.