Introduction
For some reason my son decide to put his dinosaur Top Trumps in alphabetical order (based on the first letter only). He asked me for help, so I suggest rather than trying to order a single pile, he put them in separate piles, one for each letter, then he could combine them. Before he combined them, I put them into neat piles and realised we had essentially made a bar chart.
So I found some graph paper, drew a horizontal line and started writing the letters of the alphabet, which he then continued. I showed him how to draw a bar of the right height and he immediately got the idea. When we finished, I mentioned that S is a common letter for words to start with, but it's a bit surprising that so many of his dinosaur cards start with a C. I mentioned that it's rare for words start for Q, X or Z and showed him some bar charts I had made showing the frequency of letters at the start of words.
After that, he was pretty keen to make another chart. As it happened, his Beast Quest A-Z book was on the table. He's spent several hours pouring over the beasts in this book and looking at which beasts start with each letter. I also knew it had at least one beast for every letter. So we went through the index, counting the number of beasts (and hero) and drawing bars. We noticed again that lots of names began with S, but a surprising number also began with K.
Afterwards I showed him the bar chart exercises on Khan Academy. He did pretty well with the lessons and they introduced the idea of picking a suitable range for the y-axis.