All from 9 and the last from 10

The formula ALL FROM 9 AND THE LAST FROM 10 is used to perform instant subtractions.

For example 1000 - 357 =?

We simply take each figure in 357 from 9 and the last figure from 10.

                                  

It is important to know the five pairs of numbers that add up to 10: 1 + 9 = 10, 2 + 8 = 10, 3 + 7 = 10, 4 + 6 = 10, 5 + 5 = 10.
It is important to know the four  pairs of numbers that add up to 9: 1+8=9, 2+7=9, 3+6=9,  4+5=9

10th compliment                           9th compliment
1---9                                                 1---8
2---8                                                 2---7
3---7                                                 3---6
4---6                                                 4---5
5---5                                                 5---4
6---4                                                 6---3
7---3                                                 7---2
8---2                                                 8---1
9---1                                                 9---0

All From 9 and the Last From 10 is a useful formula, as we will see.
If you apply All From 9 and the Last From 10 to 876                 
  8   7   6
   |    |    |
  1   2   4
you get 124, because you take 8 and 7 from 9 and the 6 from 10. Similarly

 3883,        64,       98,            6,                 10905,
 become
 6117,        36,       02,            4,                 89095.

Practice A   Apply All from 9 and the Last from 10 to the following:
a) 1000- 444 b) 1000- 675 c)  10000-2468 d) 100000-18276 e)10000-8998 f )10000-9888  g)10000000-1020304