Double Digit Multiplication

Multiplying by a two-digit number requires multiplying each digit in every place value being multiplied by every digit in the two-digit factor.

1. Arrange the numbers one on top of the other and line up the place values in columns. The number with the most digits is usually placed on top as the multiplicand.
2. Starting with the ones digit of the bottom number, the multiplier, multiply it by the last digit in the top number
3. Write the answer below the equals line
4. If that answer is greater than nine, write the ones place as the answer and carry the tens digit
5. Proceed right to left. Multiply the ones digit of the bottom number to the next digit to the left in the top number. If you carried a digit, add it to the result and write the answer below the equals line. If you need to carry again, do so.
6. When you’ve multiplied the ones digit by every digit in the top number, move to the tens digit in the bottom number.
7. Multiply as above, but this time write your answers in a new row, shifted one digit place to the left.
8. When you finish multiplying, draw another answer line below your last row of answer numbers.
9. Use long addition to add your number columns from right to left, carrying as you normally do for long addition.

Solve

61 x 21