SUBTRACTION
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Subtraction sums are also difficult to solve when 0 is one of the digit.
Subtraction and division are similar in nature and both these mathematical
technique are difficult when 0 is involved. Multiplication and addition are
pretty straight forward and easy to solve.
1  9  10  
9  
 
1  9  8  1 
0  0  2  8 
Here is similarly slightly difficult subtraction sum.

4  14  9  15  
 
3  9  5  9  
1  5  4  6 
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