Pre-Algebra Examples

$35.7 \cdot 6.4$

Step 1

Multiply $4$ by $7$ . Place the ones digit $(8)$ in the result line and carry the tens digit $(2)$ . There is one result line for each digit in $6.4$ .

		$2$
	$3$	$5$	. $7$
$⨯$		$6$	. $4$
			$8$

Step 2

Multiply $4$ by $5$ and add the carried $2$ . Place the ones digit $(2)$ in the result line and carry the tens digit $(2)$ . There is one result line for each digit in the $6.4$ .

	$2$	$2$
	$3$	$5$	. $7$
$⨯$		$6$	. $4$
		$2$	$8$

Step 3

Multiply $4$ by $3$ and add the carried $2$ . Place the ones digit $(4)$ in the result line and carry the tens digit $(1)$ . There is one result line for each digit in the $6.4$ .


	$3$	$5$	. $7$
$⨯$		$6$	. $4$
$1$	$4$	$2$	$8$

Step 4

Multiply $6$ by $7$ . Place the ones digit $(2)$ in the result line and carry the tens digit $(4)$ . There is one result line for each digit in $6.4$ .

		$4$
	$3$	$5$	. $7$
$⨯$		$6$	. $4$
$1$	$4$	$2$	$8$
		$2$

Step 5

Multiply $6$ by $5$ and add the carried $4$ . Place the ones digit $(4)$ in the result line and carry the tens digit $(3)$ . There is one result line for each digit in the $6.4$ .

	$3$	$4$
	$3$	$5$	. $7$
$⨯$		$6$	. $4$
$1$	$4$	$2$	$8$
	$4$	$2$

Step 6

Multiply $6$ by $3$ and add the carried $3$ . Place the ones digit $(1)$ in the result line and carry the tens digit $(2)$ . There is one result line for each digit in the $6.4$ .


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$

Step 7

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


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$
				$8$

Step 8

Add the numbers in each column. In this case, add $2 + 2$ , then place the $4$ in the result line.


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$
			$4$	$8$

Step 9

Add the numbers in each column. In this case, add $4 + 4$ , then place the $8$ in the result line.


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$
		$8$	$4$	$8$

Step 10

Add the numbers in each column. In this case, add $1 + 1$ , then place the $2$ in the result line.


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$
	$2$	$8$	$4$	$8$

Step 11

Add the numbers in each column. In this case, add $0 + 2$ , then place the $2$ in the result line.


		$3$	$5$	. $7$
	$⨯$		$6$	. $4$
	$1$	$4$	$2$	$8$
$2$	$1$	$4$	$2$
$2$	$2$	$8$	$4$	$8$

Step 12

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.

$228.48$