Instant Subtractions

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.
 
Similarly 10,000 - 1049 = 8951

 
For 1000 - 83, in which we have more zeros than
figures in the numbers being subtracted, we simply
suppose 83 is 083.
 
So 1000 - 83 becomes 1000 - 083 = 917


Try some yourself:

1)  1000 - 777       =    
 
2)  1000 - 283       =    
 
3)  1000 - 505       =    
 
4)  10,000 - 2345  =    
 
5)  10,000 - 9876  =