Kakuro Puzzle 1 - 6x6 - Step 4
Nothing simple to solve now so lets turn our attention to the bottom right block of 4 (highlighted). We can see that the 2nd from bottom row in it has to total 6. Now this can be a combo of 1 and 5 or 2 and 4 (we can't have 3 and 3 as numbers can not be repeated in a block).
Now look the last column, you will see this needs to add up to 14, which is either 5 and 9 or 6 and 8. If we cross reference this with the numbers before we can see that 5 is the only common number, therefore it must appear in the top right space.
Click here for step 5