Basic Math Examples

21 \cdot 21

$21 \cdot 21$

Step 1

Multiply using long multiplication.

Tap for more steps...

Step 1.1

Multiply

1

$1$ by

1

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

21

$21$ .


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
		$1$ $1$

Step 1.2

Multiply

1

$1$ by

2

$2$ . Place the result in the next column in the result line. There is one result line for each digit in

21

$21$ .


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$

Step 1.3

Multiply

2

$2$ by

1

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

21

$21$ .


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
	$2$ $2$

Step 1.4

Multiply

2

$2$ by

2

$2$ . Place the result in the next column in the result line. There is one result line for each digit in

21

$21$ .


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
$4$ $4$	$2$ $2$

Step 1.5

Add the numbers in each column. In this case, add

1 + 0

$1 + 0$ , then place the

1

$1$ in the result line.


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
$4$ $4$	$2$ $2$
		$1$ $1$

Step 1.6

Add the numbers in each column. In this case, add

2 + 2

$2 + 2$ , then place the

4

$4$ in the result line.


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
$4$ $4$	$2$ $2$
	$4$ $4$	$1$ $1$

Step 1.7

Add the numbers in each column. In this case, add

0 + 4

$0 + 4$ , then place the

4

$4$ in the result line.


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
$4$ $4$	$2$ $2$
$4$ $4$	$4$ $4$	$1$ $1$


	$2$ $2$	$1$ $1$
$\times$ $⨯$	$2$ $2$	$1$ $1$
	$2$ $2$	$1$ $1$
$4$ $4$	$2$ $2$
$4$ $4$	$4$ $4$	$1$ $1$

Step 2

The result of

21 \cdot 21

$21 \cdot 21$ is

441

$441$ .

441

$441$