The Minus Sign: Reading and Writing a Subtraction Sentence

This idea walks around your house all day. A shopkeeper writes down what he started with and what he sold. The number left is what still sits on the shelf. His whole notebook is subtraction sentences. This is worth learning because writing the numbers in the right order keeps your answer true to the story.

Watch for it today, and when you spot it, tell someone what you noticed and how you knew. This idea is simple once you see it. The minus sign is one flat line, and it means take away. The sentence 9 minus 4 equals 5 is read like this: nine take away four is the same amount as five.

The first number is what you started with. The second number is what left. The number after the equal sign is what stayed. Write the numbers in the order the story happened, because in subtraction the order truly matters. Try writing this story as a sentence: you had six crayons and gave two away.

That is 6 minus 2 equals 4. Notice the six comes first because that is what you started with. Writing the story in order keeps the numbers doing their right jobs. Try a few on your own, and be patient with yourself.