Long Multiplication: 840 × 8

"Long Multiplication Calculator" Calculator

Multiplicand (number to be multiplied)

Multiplier (number to multiply by)

What is 840 × 8?

Answer

840 × 8 = 6,720

840 × 8 and 8 × 840 are the same product — the order of the factors never changes the answer, only the working. Below, 840 is multiplied by 8 in a column, digit by digit.

840 × 8 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.

  840
×   8
 6720
840 × 8 = 6,720

Step-by-Step Solution

Step 1: Multiply the multiplicand by the last digit of the multiplier, 8: 840 × 8 = 6,720.

  • 0 × 8 = 0. Write 0.
  • 4 × 8 = 32. Write 2 and carry 3.
  • 8 × 8 = 64, plus the carried 3 makes 67. Write 7 and carry 6.
  • No digits are left, so the carried 6 is written in front: the partial product is 6,720.

840 × 8

=

6,720

Check It, and What It Is Not

Check by dividing back. Multiplication and division undo each other, so 6,720 ÷ 8 = 840 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.

840 × 8 is a number, not an area. If those are the sides of a room in feet, the answer is 6,720 square feet — the same arithmetic, a different question, and it is answered by the square footage calculator.

See Also

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 840 × 8? (The answer is: 6,720). Enter the multiplicand (e.g. '840') and the multiplier (e.g. '8') and hit the button. The order of the two numbers does not matter — 840 × 8 and 8 × 840 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 840

MultiplicationProduct
740 × 85,920
750 × 86,000
760 × 86,080
770 × 86,160
780 × 86,240
790 × 86,320
800 × 86,400
810 × 86,480
820 × 86,560
830 × 86,640
840 × 86,720
850 × 86,800
860 × 86,880
870 × 86,960
880 × 87,040
890 × 87,120
900 × 87,200
910 × 87,280
920 × 87,360
930 × 87,440

FAQ

What is 840 × 8?

840 × 8 = 6,720

Is 840 × 8 the same as 8 × 840?

Yes. Multiplication is commutative, so both come to 6,720. Only the working differs: this page multiplies by 8, which gives a single partial product.

How do you check that 840 × 8 = 6,720?

Divide the product back by one of the factors: 6,720 ÷ 8 = 840 exactly, with no remainder. Multiplication and division undo each other, which is what makes this check work.

What are the partial products of 840 × 8?

There is only one: the multiplier 8 has a single digit, so 840 × 8 = 6,720 is written straight under the line, with no addition step.

See Also