In the diagram below, there are 10 counters. Alex thinks they look like a fish swimming to the left.
He wonders if he can make it swim to the right. Yes, he can. But what is the smallest number of counters that he needs to move to make the fish swim to the right?
Solution
Alex manages to make the fish swim in the opposite direction by moving just three counters.
He took the three different counters and moved them as in the diagram. Now he has the fish swimming to the right!
Can he do this in any other way?
Extension
Try making a bigger fish and see how many counters you need to move to make it change direction.