Common core subtraction

Common core subtraction - counting up method of subtraction

Common core subtraction is using addition instead. Add up from the smaller number to the bigger number.

Subtraction = Addition

To subtract using the common core we use the same method as addition but the other way around

Yes Really! Subtraction is addition.

Example 1

`32-12`

`12`	`+`	`3`	`=`	`15`
`15`	`+`	`5`	`=`	`20`
`20`	`+`	`10`	`=`	`30`
`30`	`+`	`2`	`=`	`32`

		`20`

To see this step by step

Answer: `32-12=20`

Example 2

`43-13`

`13`	`+`	`2`	`=`	`15`
`15`	`+`	`5`	`=`	`20`
`20`	`+`	`10`	`=`	`30`
`30`	`+`	`10`	`=`	`40`
`40`	`+`	`3`	`=`	`43`

		`30`

To see this step by step

Common core subtraction step by step

Example 2

`43-13`


	`13`					Start with the lowest number


	`13`	`+`	`2`			Add `2` because it's then easy to get to `15`


	`13`	`+`	`2`	`=15`		`15` is the running total


	`13`	`+`	`2`	`=15`		Put the running total on the next line
	`15`


	`13`	`+`	`2`	`=15`		Add `5` because it's then easy to get to `20`
	`15`	`+`	`5`


	`13`	`+`	`2`	`=15`		`20` is the running total
	`15`	`+`	`5`	`=20`


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`					Put the running total on the next line


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`			Add `10` because it's then easy to get to `30`


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`		`30` is the running total


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`
	`30`	`+`	`10`			Add `10` because it's then easy to get to `40`


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`
	`30`	`+`	`10`	`=40`		`40` is the running total


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`
	`30`	`+`	`10`	`=40`
	`40`					Put the running total on the next line


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`
	`30`	`+`	`10`	`=40`
	`40`	`+`	`3`			Add `3` to finally get `43`


	`13`	`+`	`2`	`=15`
	`15`	`+`	`5`	`=20`
	`20`	`+`	`10`	`=30`
	`30`	`+`	`10`	`=40`
	`40`	`+`	`3`	`=43`		Check the final equals `43`


		`+`	`2`
		`+`	`5`
		`+`	`10`
		`+`	`10`
		`+`	`3`			Now add

			`30`

Answer: `43-13=30`

Answer: `43-13=30`

Example 3

`325-38`

`38`	`+`	`2`	`=`	`40`
`40`	`+`	`60`	`=`	`100`
`100`	`+`	`200`	`=`	`300`
`300`	`+`	`25`	`=`	`325`

		`287`

To see this step by step

Answer: `325-38=287`

Example 4

`264-128`

`128`	`+`	`2`	`=`	`130`
`130`	`+`	`70`	`=`	`200`
`200`	`+`	`60`	`=`	`260`
`260`	`+`	`4`	`=`	`264`

		`136`

To see this step by step

Answer: `264-128=136`

OR

`128`	`+`	`100`	`=`	`228`
`228`	`+`	`30`	`=`	`258`
`258`	`+`	`2`	`=`	`260`
`260`	`+`	`4`	`=`	`264`

		`136`

Common core subtraction step by step

Example 4

`264-128`


	`128`					Start with the lowest number


	`128`	`+`	`100`			Add `100` because it's an easy jump to `228`


	`128`	`+`	`100`	`=228`		`228` is the running total


	`128`	`+`	`100`	`=228`		Put the running total on the next line
	`228`


	`128`	`+`	`100`	`=228`		Add `30` because it's a round number to get to `258`
	`228`	`+`	`30`


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`		`258` is the running total


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=228`
	`258`					Put the running total on the next line


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`
	`258`	`+`	`2`			Add `2` because it's then easy to get to `260`


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`
	`258`	`+`	`2`	`=260`		`260` is the running total


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`
	`258`	`+`	`2`	`=260`		Put the running total on the next line
	`260`


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`
	`258`	`+`	`2`	`=260`
	`260`	`+`	`4`			Add `4` to finally get to `264`


	`128`	`+`	`100`	`=228`
	`228`	`+`	`30`	`=258`
	`258`	`+`	`2`	`=260`
	`260`	`+`	`4`	`=264`		Check the final equals `264`


		`+`	`100`
		`+`	`30`
		`+`	`2`
		`+`	`4`			Now add

			`136`

Answer: `264-128=136`

Answer: `264-128=136`