The Four Methods

All you need to know about the four methods

By Eva

Column addition • Colum addition is really easy when you

know how to do it. Lets take at this sum

below us. • HTU ]• 123• 235

How to do it

• Write down your sum and label the numbers into units ten hundreds and thousands. Start adding using the units and then work up next doing tens ect.. Do it a bit like this. If you have a carrying one all you have to do is put the number to the right in the box and then put the other number below the box into the next column. And when you do the next sum add it on. A bit like this. So if you had to carry a 2 you would put it under the box and add it on to the next sum!!

Subtracting

• Subtracting is a lot like adding you do the same thing but only take the number away and remember you don’t carry you borrow addition is carrying!!

• 123-

• 112

Column multiplication • So first write your sum and do 5x5which is 25 so write the 5 in and

carry the 2 over next do 4x5 and because you have the 2 add it on not times it on remember add it on to the total of that.4x5 is 20 add the 2 is 22 so you put the 2in the box and them put the other 2 in the hundreds column because you have nothing else to times it by. Then when your confident at doing that go on to 3 digit by 2 digit it is the same so remember you need to times the five by all the numbers at the top. And one more thing when you carry add it on not times it on!!!

• t u• 45• 5•

How to do it

• Do 5-4 because there in the unit• column. So now write your answer in the box

• under the units column. Next do 4-6 but on this one you have to borrow. What you need to do is borrow from the 4 so you need to cross out the four and change it to a 3 and make the other four a 14 because it was a four but you’ve added a 1 to it so it makes it

fourteen. So now you do 6-14 H T U• 43 14 5• 3 6 4• 0 8 1

Column division

• So first write your sum as always. Now first see how many 2 go into 2 and then write it above the box. Then see how many 2 go into 3 but because you got a remainder 1 you put it next to the four all now you call the 4, 14. But you still put 1 above the three on the box because 2 goes into 3 once. Now you do how many 2 go into 14 which is 7 so now you know how to do column division.

• 117

• 2 2314