Number & Operations in Base 10
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In kindergarten, Numbers and Operations in Base 10 includes an understanding of the numbers 11 to 19 as a foundation for place value.
Kindergarten teachers help their students lay the foundation for understanding the baseten system by drawing special attention to the number 10. Students compose and decompose numbers from 11 to 19 into 10 ones and some further ones. Students use objects or drawings and record each composition or decomposition with a drawing or equation (e.g., 16 = 10 + 6).
The end of kindergarten expectations are that children demonstrate the ability to add and subtract numbers from 11 to 19. This includes understanding different ways to compose or decompose a number. For example, 17 is equal to 15 + 2 and also 12 + 5.
Vocabulary List:
Here is a list of important vocabulary words, from the California Mathematics Frameworks, that children can learn to use correctly by the end of their kindergarten year.

Number

Add

Subtract

Adding

Subtracting

Make 10

All together

Equals

The same as

In all

Total

Amount left
What it looks like:
A child will draw a group of 12 circles and another group of 7 circles to show that 12 + 7 equals 19.
A child will use a group of 15 objects to show that taking 7 away results in a group of 8 objects.