Multiplying by 125

Use the following steps to multiply mentally by 125.

• Multiply the number by 5 first, then divide that product by 4.

• If the remainder is 0, write 00 after the quotient.

• If the remainder is 1, write 25 after the quotient.

• If the remainder is 2, write 50 after the quotient.

• If the remainder is 3, write 75 after the quotient.

Example:

27 × 125 =

Multiply 27 by 5, and then divide by 4.

27 × 5 = 135, 135 ÷ 4 = 33 (remainder 3)

Since the remainder is 3, write 75 after 33.

27 × 125 = 3375

Example:

661 × 125 =

Multiply 661 by 5, and then divide by 4.

661 × 5 = 3305, 3305 ÷ 4 = 826 (remainder = 1)

Since the remainder is 1, write 25 after the 826.

661 × 125 = 82625