What Addition Means: Joining Two Groups to Make One Bigger Group

This idea walks around your house all day. A cook adds two baskets of tomatoes into one pot. A family adds cousins to the table at supper. Whenever two groups become one group, addition is happening. This is worth learning because addition is the first operation, and everything from money to measuring uses it.

Watch for it today, and when you spot it, tell someone what you noticed and how you knew. This is a good thing for a young mathematician to know. Addition means putting groups together. Set three acorns on the table. Set two more beside them. Now push them into one pile and count: one, two, three, four, five.

Three and two joined together make five. Nothing was thrown away and nothing was added secretly, so the total is simply everything you started with, gathered into one group. That is all addition is. Every addition problem you will ever meet is some version of joining. Here is a common mix up.

Some people count the first pile again after joining, and end up counting some objects twice. Push the two piles fully together first, then start your count from one and go straight through. Counting once, carefully, beats counting twice in a hurry. Do it carefully rather than quickly, and thank God for a mind that can learn.