You will learn that whole numbers can be put together to compose a greater number. Whole numbers can also be broken apart to decompose into two lesser numbers!
To better understand composing & decomposing numbers…
LET’S BREAK IT DOWN!
Decompose a number
Decomposing a number means taking a whole number and breaking it into two smaller parts. To decompose the number 5, you can break it into smaller parts of 4 and 1, or 3 and 2.
Use a number bond to show parts.
A number bond is a tool you can use to show parts of a whole. A number bond has one circle on top and two circles on the bottom. The top number shows the whole. The bottom numbers show the parts.
Decompose 8 using a number bond.
To show 8 in a number bond, put 8 in the top circle. Then the parts go in the lower circles. 2 and 6 make 8. 2 and 6 can go in the lower circles.
Compose a number.
Composing a number means taking two lesser numbers and combining them to make a greater whole number. A group of 4 and a group of 2 make 6.
Compose 9 using a number bond.
9 goes in the top circle. 6 and 3 make 9 so the numbers 6 and 3 can go in the lower circles. You can say 6 and 3 make 9 OR 3 and 6 make 9.
COMPOSING & DECOMPOSING NUMBERS (1-10) VOCABULARY
COMPOSING & DECOMPOSING NUMBERS (1-10) DISCUSSION QUESTIONS
[Draw a number bond showing 9 broken into 4 and an unknown amount.]
What part is missing from this number bond? How do you know?
[Draw a number bond showing an unknown number broken into 3 and 7.] What whole is missing from this number bond? How do you know?
Choose Your Free Trial Period
Get 90 Days Free
By inviting 4 other teachers to try it too.
Skip, I will use a 7 days free trial
Enjoy your free 90 days trial