Multiply two-digit numbers by doing two separate multiplication problems, one with the tens column of one of the numbers and one with the units column of that number, and adding the answers together. The sum of the two numbers is the answer to the multiplication problem.
- Multiply the digit in the ones column
Multiply the ones-column digit in one of the two-digit numbers by the other two-digit number. For example, if the problem is 24 x 31, multiply 4 x 31 to get 124. Remember or record this number.
- Multiply the digit in the tens column
Multiply the tens-column digit in the first number by the two-digit number. Using the above example, multiply 2 x 31 to arrive at the answer 62.
- Add the numbers
Add the two numbers together, inserting a zero in the ones column of the second number. In the above example, add the zero to 62 to give 620, then calculate 124 + 620. The answer is 744, which is the solution to 24 x 31.