Digit Dog saw the Ladybird Box problem on www.nrich.maths.org/144 and thought he’d try it out.
The Challenge
The box has 9 little square compartments. Can you put the 6 ladybirds in the box so that there are just 2 ladybirds in every column and every row?
I wonder how many ways there are to do the puzzle?
Does it matter which compartment you put the first ladybird in?
What do you need to keep checking? Remember that each row and each column can only have 2 ladybirds in them.
How many empty compartments will there be?
Record your work on this grid
Look at your friend’s solution. What is the same? What is different?
Digit Dog Challenges 