Tutorial 1 
Use the formula ALL FROM 9 AND THE LAST FROM 10 to perform instant subtractions.


 For example 1000  357 = 643
We simply take each figure in 357 from 9 and the last figure from
10.
So the answer is 1000  357 = 643
And thats all there is to it!
This always works for subtractions from numbers consisting of a
1 followed by noughts: 100; 1000; 10,000 etc.




