se the traditional method or rectangular method to solve the problem.

Question

se the traditional method or rectangular method to solve the problem.
345 x 21

GPT-4o mini · Answer

To solve the multiplication problem $ 345 \times 21 $ using the traditional or rectangular method, you can follow these steps: 1. **Setting up the problem**: Write the numbers in a column, with $ 345 $ on top and $ 21 $ below it. ``` 345 x 21 ``` 2. **Multiply the bottom number (1) by the top number (345)**: - $ 1 \times 345 = 345 $ Write this result below the line. ``` 345 x 21 ----- 345 (This is 345 * 1) ``` 3. **Multiply the bottom number (2) by the top number (345)**, but remember that this 2 is in the tens place (which is actually $ 20 $): - $ 2 \times 345 = 690 $ - Since you are multiplying by 20, you add a zero to this result: ``` 345 x 21 ----- 345 (This is 345 * 1) +6900 (This is 345 * 20, i.e., 690 with one zero) ``` 4. **Add the results together**: ``` 345 +6900 ----- 7245 ``` So, $ 345 \times 21 = 7245 $.