Sudoku - Day 3

Ok, we solved three numbers using some heavy logic last time. Now I want to show you a neat trick regarding 3 numbers in a row or column that are all in one box.

Take a look at box 4 column 1: Notice all the numbers are filled in. This is a secret code indicating that you can probably solve something using that information. So let's look again at column 2. Note that [A6] is 7 eliminating [A1 - A3] being 7. Well that also eliminates box 1, column 2 for being a 7 as well. And the 7 in [D1] eliminates [A1, B1, C1] from being 7 which means that the 7 for box 1 must be in column 3. Now looking at the puzzle, you can see that [B3] and [C3] are candidates, but look further into the logic.

If the 7 in box 1 is in column 3 and the 7 in box 2 is (already) in column 1 then the 7 for box 3 must be in column 2, and (Bonus!) there is only 1 location open in box 3 column 2, [G2]. Put a nice fat 7 in [G2].

Now, let's focus on box 7. Look at the 4 in [E1] eliminating all available squares except [H3]. Put a big fat 4 in [H3].

Let's kill box 7 and place the 8 in [G1] and the obvious 2 in [H2].

So, here we are at the end of day three.

The doctor.