I had a cardboard box in which I wanted to store my tools. I wanted some form of partitions in it so that I could categorize the tools. While going through the many instructibles on cardboard use, I got an idea to create partitions using the lids of the box, which were of the same width. And to add to it the fact that their length matched the length and the breadth of the box. So here is an instructible about how I did it.

Step 1: Materials Needed

A Box of cardboard with 4 lids
a knife or cutter
a scale to measure
a marker or pen

Step 2: Cut the Lids

cut the lids at their joints
measure the length of each lid

Step 3: Divide

Divide the length measured in the previous step into 3 equal parts
Mark them with the marker

Step 4: Cut Half the Divisions

If the box is not a strict square, it should have 2 pairs of lids of different lengths.
First thing is to mark which side of the lid will stay up.
Then we have to divide the lines that have been marked in the previous step to half.
After that, we have to cut the lids along the lines, upper half for the first pair and lower half for the second pair

Step 5: Interlock the Cut Ends

After that the final step is interlocking the cut ends to form a grid.
This grid when kept in the box gives 9 partitions of equal sizes.
We can put our stuff in it as it is or we can fix the sides using tape to give extra strength to it
The final step is beautification which I didn't do :)