Long Multiplication: 900 × 9

"Long Multiplication Calculator" Calculator

Multiplicand (number to be multiplied)

Multiplier (number to multiply by)

What is 900 × 9?

Answer

900 × 9 = 8,100

900 × 9 and 9 × 900 are the same product — the order of the factors never changes the answer, only the working. Below, 900 is multiplied by 9 in a column, digit by digit.

900 × 9 in a Column

The multiplicand goes on top, the multiplier underneath, both aligned on the right. The multiplier has a single digit, so there is one partial product and the answer goes straight under the line.

  900
×   9
 8100
900 × 9 = 8,100

Step-by-Step Solution

Step 1: Multiply the multiplicand by the last digit of the multiplier, 9: 900 × 9 = 8,100.

  • 0 × 9 = 0. Write 0.
  • 0 × 9 = 0. Write 0.
  • 9 × 9 = 81. Write 1 and carry 8.
  • No digits are left, so the carried 8 is written in front: the partial product is 8,100.

900 × 9

=

8,100

Check It, and What It Is Not

Check by dividing back. Multiplication and division undo each other, so 8,100 ÷ 9 = 900 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.

900 × 9 is a number, not an area. If those are the sides of a room in feet, the answer is 8,100 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 900 × 9? (The answer is: 8,100). Enter the multiplicand (e.g. '900') and the multiplier (e.g. '9') and hit the button. The order of the two numbers does not matter — 900 × 9 and 9 × 900 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 900

MultiplicationProduct
800 × 97,200
810 × 97,290
820 × 97,380
830 × 97,470
840 × 97,560
850 × 97,650
860 × 97,740
870 × 97,830
880 × 97,920
890 × 98,010
900 × 98,100
910 × 98,190
920 × 98,280
930 × 98,370
940 × 98,460
950 × 98,550
960 × 98,640
970 × 98,730
980 × 98,820
990 × 98,910

FAQ

What is 900 × 9?

900 × 9 = 8,100

Is 900 × 9 the same as 9 × 900?

Yes. Multiplication is commutative, so both come to 8,100. Only the working differs: this page multiplies by 9, which gives a single partial product.

How do you check that 900 × 9 = 8,100?

Divide the product back by one of the factors: 8,100 ÷ 9 = 900 exactly, with no remainder. Multiplication and division undo each other, which is what makes this check work.

What are the partial products of 900 × 9?

There is only one: the multiplier 9 has a single digit, so 900 × 9 = 8,100 is written straight under the line, with no addition step.

See Also