Every row and every column of the grid gets the numbers 1 to 4 - each exactly once. Just like a mini sudoku.
New are the signs between two squares. They tell you which of the two squares gets the bigger number.
The point of the sign always aims at the smaller number. The open side faces the bigger one. In 2 < 4 the point sits at the 2.
A lying sign belongs to the two squares to its left and right. A standing sign belongs to the two squares above and below it.
The best start is a sign that aims at an edge square. If the point aims at a square, no 4 can go there. If the open side faces it, no 1 can go there.
Example
For parents
What does this exercise practice?
The greater-smaller grid practices the reading direction of < and > - not as a quiz question but as a tool. The sign is the only clue that gets you anywhere, so it has to be read correctly or nothing moves at all. A misread does not produce a wrong number in a box, it produces a dead end - and the child notices it without help.
Common pitfalls
The most common mistake is mixing up the two sides. Remember the point - it is small and it aims at the small number. The second stumbling block are the standing signs. They work from top to bottom, not from left to right. A standing sign is wider than it is tall, a lying one is taller than it is wide.
How to practice at home
Draw two playing cards and lay them side by side. The child puts a pencil between them so that the tip aims at the smaller card. Then lay the cards one above the other - the pencil has to turn with them. After ten rounds the reading direction sticks.
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