Composing means putting together. Decomposing means taking apart. You can decompose the numbers 11 – 19 into 10 and some more.
To better understand composing & decomposing…
LET’S BREAK IT DOWN!
Decompose the number 13.
Decomposing means to take apart. You can decompose 13 into 10 and some more. 13 is 10 and 3 more.
Decompose the number 15.
There are 15 kittens in a pile. You can decompose 15 into 10 and some more. 15 is 10 and 5 more.
Use a ten frame to show 10 and some more.
You have 12 stickers. You put your stickers into ten frames. 10 stickers go into one ten frame. There are 2 stickers left. They go into another ten frame. 12 is 10 and some more.
Compose the number of bugs.
Composing means to put together. You have 10 bugs and 4 more bugs. You have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 bugs in all. 10 and 4 more is 14.
Compose the number of race cars.
You have 10 batteries and 9 more batteries. How many do you have in all? 10 batteries go in one 10 frame: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. 9 go in a second ten frame: 11, 12, 13, 14, 15, 16, 17, 18, 19. 10 and 9 more is 19.