Multiply double digits by first multiplying the whole top number by the ones digit, then by the tens digit by using a zero as a placeholder and then adding the two products.
- Arrange the numbers
Place the two numbers with their digits lining up, and draw a line below them to signify multiplication. This makes it easier to keep track of the numbers while working out the problem.
- Multiply the ones digit of the bottom by the ones digit of the top
Consult multiplication tables if necessary to determine this product. For example, when multiplying 43 and 53, the two 3s would be multiplied to yield 9. Write this 9 in the ones digit of the product.
- Carry extra digits to the tens place.
If the product of the ones digits yielded a double-digit number, write the ones digit normally, and write above the tens digit of the top number the number that is to be carried. For example, if the ones digits were 3 and 4, the result would be 12. A 2 would be in the ones digit, while the 1 to represent 10 would be above the tens digit.
- Write a zero below the ones product.
The zero represents a placeholder because now, the tens are being multiplied.
- Repeat the multiplication process with the tens digit on the bottom.
Double-digit multiplication involves adding two products, one for the ones digit and one for the tens digit.
- Add the two products.
Doing this will yield the result of multiplying two double-digit numbers.