The attached is 4 tables where you have to figure out the missing number. For each table, you can only use 0-9 numbers once (not including the given numbers).
Please see the attached file for the complete solution.
Operate from left to right & top to bottom.
8 + 8 - 9 = 7
/ / - x
4 x 2 - 3 = 5
+ - - +
0 + 1 - 0 = 1
= = = =
2 x 3 x 6 = 36
Block Notation: (row,column). That is (2,3) means the block in the second row third column. Blocks refer only to numbers containing blocks.
We start with the obvious: block (4,3)=6 and block (2,1)=4.
Now, blocks (1,4) and (2,4) must be 7 and 5 since this is the only combination that can satisfy the operations in the 4th column.
Note that between blocks (1,2) and (2,20 there is a division operation. This suggests that the only numbers that can occupy these blocks are either 8 or 9, since these are the only non-prime numbers left in the first ten digits. If block (1,2)=9 then block (2,2) =3 and (3,2)=0. However, this implies that (3,3)=-1 which is ...
This solution shows how to solve the checker-tile problems in an attached Word document and PDF copy.