Long Decimal Multiplication

Long multiplication is where you multiply in columns. Shift and add multiplication.

     123
   × 456
   =====
     738  (this is 123 × 6)
    615   (this is 123 × 5, shifted one position to the left)
 + 492    (this is 123 × 4, shifted two positions to the left)
   =====
   56088

	1	5	2	1
X			2	4
	6	0	8	4	A
	2
3	0	4	2	0	B
1
3	6	5	0	4
		1
## Multiply the units to make row A
1. 1 x 4 = 4
2. 2 x 4 = 8
3. 5 x 4 = 20, so carry the 2
4. 1 x 4 = 4, add the carried 2 = 6
## Multiply the 10s column to make row B
1. Put a zero in the units column
2. 1 x 2 = 2
3. 2 x 2 = 4
4. 5 x 2 = 10, write a zero, carry the 1
5. 1 x 2 = 2, add the 1 = 3
## Add rows A and B
Normal addition rules.
Answer is 36504.