## Contents

Connections to the 3 Curriculum Threads

Featured Standards for Mathematical Practice

## Connections to the 3 Curriculum Threads

Learn more about the 3 Curriculum Threads

**Operations: **Coming soon!

**Number: **Coming soon!

**Equivalence: **Coming soon!

## Content Standards Addressed

### Cluster K.NBT.A: Work with numbers 11-19 to gain foundations for place value.

**K.NBT.A.1: **Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.

## Featured Standards for Mathematical Practice

**S.MP.4. Model with mathematics.** Students use various strategies (circling, ten-frames, rekenrek, etc.) to model the numbers 11-19.

**S.MP.7. Look for and make use of structure.** Students explore the base ten system as it relates to the numbers 11-20 to see how each number is created from ten ones and some more ones.

The Ten Frame structure allows students to organize a group of items into a set of ten and some ones.

## Major Representations Used

Rekenrek is a visual structure of the numbers 1-20. (a double ten frame, side-by-side, can be used in place of this)

The Ten Frame structure allows students to organize a group of items into a set of ten and some ones.

Unifix cubes for students to build numbers and objects to count (beans, counters, etc.).

Number bonds

## Common Misconceptions

- Students may believe that the numbers 11-19 are each a separate unit and not a continuation of the counting base-ten pattern.
- Students may believe that each number is an individual unit and not see how ten is nested within each number 11-19.
- Students often confuse number names 12 as twoteen or twelveteen 15 as fiveteen or fifty. They may also expect to see the five come first in the number because that is what they hear first.