The Correct Answer is 5
Use the beads to help you count the kids.
First, there are 2 kids riding bikes. Add 3 more kids who join them.

Look at the first bead picture. It shows 2 beads for the first group and 3 beads for the kids joining.

Now look at the next picture. When we slide all the beads together, we see there are 5 beads in total.
So there are 5 kids riding bikes in all!