How Many in All and How Many More: Answering Questions from a Graph

This idea walks around your house all day. Numbers are collected so decisions can be made. A shop that sells more apples than pears orders accordingly. This is worth learning because data becomes useful only when someone asks it questions.

Watch for it today, and when you spot it, tell someone what you noticed and how you knew. Ask yourself where else the same idea might be hiding, then go and look.

This idea is simple once you see it. Graphs answer questions. To find how many in all, add every bar together. To find how many more one group has, subtract the smaller bar from the taller one.

If apples show six and pears show four, then there are ten pieces of fruit in all and two more apples than pears. All your addition and subtraction skills now work on real information you gathered yourself.

Try asking three different questions of the same graph. How many in all, how many more, and which had the fewest. One graph can answer many questions, which is what makes collecting the data worth the effort. Try a few on your own, and be patient with yourself.