To multiply multi-digit numbers, use the following steps:
- Write the numbers: Align them vertically by the rightmost digits.
- Multiply each digit: Start with the bottom number's rightmost digit, multiplying it by each digit of the top number.
- Record the result: Write the result below, aligning it properly based on the position of the digit being multiplied.
- Repeat for each digit: Move to the next digit in the bottom number and repeat the process, shifting one position to the left for each new digit.
- Add the results: Finally, sum all the results to get the final product.
For example, for 23 × 45:
- 23 × 5 = 115 (write this down)
- 23 × 4 (actually 40) = 92 (shift this left and write down)
- Add 115 + 920 = 1035.
So, 23 × 45 = 1035.