Yesterday's after-school sign-up sheet is in. Picture the four activities our class could choose: football, art, coding and choir. One of them was picked by far more pupils than the others. Which do you think won, and exactly how many pupils do you think chose it?

Watch the bar chart on the board. We'll read four things, always tracing each bar across to the scale instead of guessing by eye:

• the tallest bar's value
• the shortest bar's value
• how many more one bar shows than another
• the total of all the bars added together

Now we read this chart of favourite school dinners together: Roast, Pasta, Curry and Fish. First we read the Roast bar. Then we read the Fish bar. Next we work out how many more chose Roast than Fish. Finally we add all four bars to find how many pupils were asked altogether.

Now we work through these charts together, each a little harder. Each chart asks one question:

• read the tallest bar and say its exact value
• find the shortest bar
• work out how many more the tallest shows than the shortest
• read the tallest bar, then add every bar to find the total