Pre-Algebra Examples

$10999 \cdot 1.09$

Step 1

Multiply $9$ by $9$ . Place the ones digit $(1)$ in the result line and carry the tens digit $(8)$ . There is one result line for each digit in $1.09$ .

				$8$
	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
					$1$

Step 2

Multiply $9$ by $9$ and add the carried $8$ . Place the ones digit $(9)$ in the result line and carry the tens digit $(8)$ . There is one result line for each digit in the $1.09$ .

			$8$	$8$
	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
				$9$	$1$

Step 3

Multiply $9$ by $9$ and add the carried $8$ . Place the ones digit $(9)$ in the result line and carry the tens digit $(8)$ . There is one result line for each digit in the $1.09$ .

		$8$	$8$	$8$
	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
			$9$	$9$	$1$

Step 4

Multiply $9$ by $0$ and add the carried $8$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .

		$8$	$8$	$8$
	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
		$8$	$9$	$9$	$1$

Step 5

Multiply $9$ by $1$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$

Step 6

Multiply $0$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
				$0$

Step 7

Multiply $0$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
			$0$	$0$

Step 8

Multiply $0$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
		$0$	$0$	$0$

Step 9

Multiply $0$ by $0$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$

Step 10

Multiply $0$ by $1$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
$0$	$0$	$0$	$0$	$0$

Step 11

Multiply $1$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
$0$	$0$	$0$	$0$	$0$
			$9$

Step 12

Multiply $1$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
$0$	$0$	$0$	$0$	$0$
		$9$	$9$

Step 13

Multiply $1$ by $9$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
$0$	$0$	$0$	$0$	$0$
	$9$	$9$	$9$

Step 14

Multiply $1$ by $0$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


	$1$	$0$	$9$	$9$	$9$
$⨯$			$1$	. $0$	$9$
	$9$	$8$	$9$	$9$	$1$
$0$	$0$	$0$	$0$	$0$
$0$	$9$	$9$	$9$

Step 15

Multiply $1$ by $1$ . Place the result in the next column in the result line. There is one result line for each digit in $1.09$ .


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$

Step 16

Add the numbers in each column. In this case, add $1 + 0 + 0$ , then place the $1$ in the result line.


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
						$1$

Step 17

Add the numbers in each column. In this case, add $9 + 0 + 0$ , then place the $9$ in the result line.


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
					$9$	$1$

Step 18

Add the numbers in each column. In this case, add $9 + 0 + 9$ , then place the $8$ in the result line and carry the $1$ .


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
				$8$	$9$	$1$

Step 19

Add the numbers in each column. In this case, add $8 + 0 + 9 + 1$ , then place the $8$ in the result line and carry the $1$ .


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
			$8$	$8$	$9$	$1$

Step 20

Add the numbers in each column. In this case, add $9 + 0 + 9 + 1$ , then place the $9$ in the result line and carry the $1$ .


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
		$9$	$8$	$8$	$9$	$1$

Step 21

Add the numbers in each column. In this case, add $0 + 0 + 0 + 1$ , then place the $1$ in the result line.


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
	$1$	$9$	$8$	$8$	$9$	$1$

Step 22

Add the numbers in each column. In this case, add $0 + 0 + 1$ , then place the $1$ in the result line.


		$1$	$0$	$9$	$9$	$9$
	$⨯$			$1$	. $0$	$9$
		$9$	$8$	$9$	$9$	$1$
	$0$	$0$	$0$	$0$	$0$
$1$	$0$	$9$	$9$	$9$
$1$	$1$	$9$	$8$	$8$	$9$	$1$

Step 23

To find the number of decimal places needed in the answer, add the number of decimal places in the multiplier and multiplicand. In this case, there is a total of $2$ , so the answer must have $2$ decimal places as well.

$11988.91$