Sir Crab Multiplier is a math character who depicts multiplication as combining neatly (by 2s, 3s, 4s, ...) where the quantities being joined are equal numerically. Use the story and follow-up below to tell about the jobs he does. Emphasize that multiplication is about combining things the same and explain that the word “neatly” is used with the word “combining” because the result in everyday living usually looks neat. Have elementary school students mime the actions implicit in the jobs in the follow-up to acquire a literal feel for multiplication as combining neatly.
Like Motley Crab Adder, Sir Crab Multiplier is a combiner, but he only joins things that are all the same [numerically], whereas Motley does not worry if the things she joins are the same [numerically]. When Sir Crab puts things together, the result usually looks neat, like a brick wall, a tiled hallway, or shoes on a rack. That is why we say he combines neatly. No one knows why Sir Crab always combines neatly; that is simply the way he is. Do you know anyone like Sir Crab? Are you ever like him? Explain.
• Baking a tray of cookies, laying out silverware for dinner, and putting pennies in rolls are Sir Crab Multiplier jobs around the house. Show me (mime) what it looks like to do those jobs. What are some other Sir Crab Multiplier jobs around the house? Show me (mime) what it looks like to do those jobs.• Converting hours to minutes, meters to centimeters, and dollars to dimes are Sir Crab Multiplier jobs at school. Show me (mime) what it looks like to do those jobs. What are some other Sir Crab Multiplier jobs at school? Show me (mime) what it looks like to do those jobs.
• What are some other ways to say (or imply) combine “neatly”? Make a list of these words and post it where it can be seen and extended. Include words like accrue, accumulate, augment, bear, beget, breed, build, burgeon, compound, enlarge, expand, explode, heighten, gain, generate, grow, heighten, inflate, intensify, magnify, mount, multiply, mushroom, proliferate, propagate, reproduce, rise, snowball, spawn, and swell. These words transcend the contrived language in arithmetic word problems and heighten student’s awareness of the many everyday occurrences of multiplication in and out of schoo.
• Optional: Write and illustrate a story about Sir Crab Multiplier.