Long Multiplication: 15 × 12

"Long Multiplication Calculator" Calculator

Multiplicand (number to be multiplied)

Multiplier (number to multiply by)

What is 15 × 12?

Answer

15 × 12 = 180

15 × 12 and 12 × 15 are the same product — the order of the factors never changes the answer, only the working. Below, 15 is multiplied by 12 in a column, digit by digit.

15 × 12 in a Column

The multiplicand goes on top, the multiplier underneath, both aligned on the right. Each digit of the multiplier produces its own partial product, and the partial products are added up.

  15
× 12
  30
+150
 180
15 × 12 = 180

Step-by-Step Solution

Step 1: Multiply the multiplicand by the last digit of the multiplier, 2: 15 × 2 = 30.

  • 5 × 2 = 10. Write 0 and carry 1.
  • 1 × 2 = 2, plus the carried 1 makes 3. Write 3.

Step 2: The next digit of the multiplier is 1, and it stands for 10: 15 × 10 = 150.

  • 5 × 1 = 5. Write 5.
  • 1 × 1 = 1. Write 1.

30 + 150

=

180

Adding the partial products finishes the work: 15 × 12 = 180.

Check It, and What It Is Not

Check by dividing back. Multiplication and division undo each other, so 180 ÷ 12 = 15 must come out exactly, with no remainder.

Fractions are a different calculation. Both factors here are whole numbers; for 2/3 or 2 3/4 use the fraction multiplication calculator, which multiplies numerators and denominators separately.

15 × 12 is a number, not an area. If those are the sides of a room in feet, the answer is 180 square feet — the same arithmetic, a different question, and it is answered by the square footage calculator.

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About "Long Multiplication Calculator" Calculator

This calculator multiplies two whole numbers the way it is done on paper: digit by digit, carrying where the column overflows, then adding the partial products together. For example, it can help you find out what is 15 × 12? (The answer is: 180). Enter the multiplicand (e.g. '15') and the multiplier (e.g. '12') and hit the button. The order of the two numbers does not matter — 15 × 12 and 12 × 15 are the same product — so either number can go on top. Fractions and mixed numbers belong to the fraction multiplication calculator, and the reverse operation is long division.

"Long Multiplication Calculator" Calculator

Multiplicand (number to be multiplied)

Multiplier (number to multiply by)

Products of 15

MultiplicationProduct
15 × 115
15 × 230
15 × 345
15 × 460
15 × 575
15 × 690
15 × 7105
15 × 8120
15 × 9135
15 × 10150
15 × 11165
15 × 12180

FAQ

What is 15 × 12?

15 × 12 = 180

Is 15 × 12 the same as 12 × 15?

Yes. Multiplication is commutative, so both come to 180. Only the working differs: this page multiplies by 12, which gives 2 partial products.

How do you check that 15 × 12 = 180?

Divide the product back by one of the factors: 180 ÷ 12 = 15 exactly, with no remainder. Multiplication and division undo each other, which is what makes this check work.

What are the partial products of 15 × 12?

They are 30 + 150, and adding them gives 180.

See Also