Composing Numbers

Composer to 10

Knows number combinations to totals of 10. Quickly names parts of any whole, or the whole given parts. Doubles to 20. Uses inverses, such as a known addition combination to figure out a related subtraction combination.

Note: The goal for this level goes beyond simply memorizing math facts. The goal is knowing the “breakaparts,” which means the paired values that compose a target number. For example, the breakaparts for the target 4 are: 0 and 4, 1 and 3, 2 and 2. Knowing breakaparts means knowing the component parts in any order. In other words, knowing that 2 and 3 or 3 and 2 are breakaparts for the target 5. Children learn doubles fairly early on, such as 4 and 4 for the target 8 and 5 and 5 for the target 10. Also early are combinations including 1, such as 7 and 1 for the target 8 or 9 and 1 for the target 10. Later, they learn combinations with 2 as the first addend, such as 2 and 6for the target 8 or 2 and 7 for the target 9. The last developing are combinations in which 3 and 4 are the smallest parts, such as 3 and 5 for the target 8 or 4 and 6 for the target 10.

Activities

You may see this:

Other Examples:

"9 and 9 is 18."
Shown 10, then 7 are secretly hidden and the remaining 3 are shown, a child quickly says “7 are hidden.”

Help your student become a(n) Composer to 10

Distributed practice is key to achieving fluency. This means frequent but brief practice with activities that promote meaningful knowledge of all combinations up to totals of 10. Like most composing number levels, they use visual models (conceptual subitizing) and thinking strategies. For example, children understand the ideas of "add (or subtract) zero" (same number) and "add (or subtract) 1" (next or previous number). They also use commutativity (if I know 8 + 2, I know 2 + 8) and associativity (7 + 9 + 1 is 7 + (9 + 1) is 7 + 10 is 17). Activities do not use timed tests and drill without understanding. Group related facts. Choose number combinations that connect to/relate to specific related strategies (+/- 1 or 2; +/- 9 or 10). Ask students to notice patterns they see. Connect addition and subtraction.