Easiest way to quick Subtraction-Group in to two's Method

• Group in to two's (Starting from the right)

Example, 1) 15627 - 1211 = ?

                ⇒   1 56 27

                    -    12 11

                       1 44 16.

It's easier to think "27 - 11 = 16" & "56 - 12 = 44"

So we get, 15627 - 1211 =14416.

                  1) 4812 - 1598 = ?

                ⇒    48 12

                    -   15 98

                         32 14

 A bit like School, 12-98, Make it 112-98 = 14 carry one

Do 48-15 then subtract one. i.e. 48-15 = 33, 33-1 = 32.

So we get,  4812 - 1598 = 3214.