Here are my two boys and the two neighbor boys when we went to the zoo. The penguin pictures are a long wall with all the species of penguins pictured and their average size so kids can see how they measure up. Nick and Jonathon are in front of the end where the Emperor is pictures, and the penguins get smaller as you go farther to the right.
Ryan (on the far left) is 13 (he'll be 14 in September), and Kyle is 11 and will be 12 in December. Ryan is far past me, and Kyle has caught me (and I am almost 5'10"). Nick is just a little more than a year younger than Kyle and Jonathon is 6.