Each row and column must contain the numbers 1 to 9 and only one instance of each number is allowed to be entered into a row or column.
The inequality signs, < > or arrows, always point to a lesser number.
More than and less than explained:
Number 9 points to a lesser number, which in this case is number 6. Number 8 points to a lesser number, which in this case is number 7. The number 7 also points to a lesser number, which in this case is the number 6.
This means that the boxes to the left and below the number 6 must be more than itself. The box to the left of the number 7 must also be more than itself.
The most obvious clue is the number 2 in cell F3. As you can see, this cell has an arrow pointing to both E3 and F4, which means that these cells must both contain the number 1.
A9 contains a number 3 and has an arrow pointing to cell A8. The number in A8 must be the number 1 because there is already a number 2 in cell A7.
In row C the number 1 must go into C5, this is due to the fact that columns A, E, F and G already have the number 1 in them, and cells D5 and B5 have arrows pointing away from them.
Cell B1 must contain the number 1 because columns A, C, E, F, G and I all contain the number 1, cell D3 has an arrow pointing to a number 1 and H1 has an arrow pointing away from it.
I2 contains a number 1. Can you work out why?
Take a look at images 5, 6, 7, and 8, and work out why the numbers have been put into those particular shaded cells.
Look for low numbers such as 2 or 3 that have a “less than” sign. If the number is a 2, the cell it points to must be a number 1.
If the number is a 3 with a “less than” sign and the row or column it points to already contains a number 2 the cell it points to must be the number 1, similarly, if the row or column it points to already contains a number 1 the cell must be number 2
Look for high numbers such as 7 or 8 with the “more than” (open end of the arrow pointing away from them) sign, and use the same strategies as above.