In this Unit students will discover the pattern of our base ten number system and how the teen numbers 1119 are composed of ten ones and some more ones. This builds on students understanding of composing ten and counting to 100. Students may struggle with the understanding that the numbers 1119 are not each a separate unit but a continuation of the counting baseten pattern where the ten is nested in the numbers 1119.
Key Concepts:
 The numbers 1119 are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones. (Lesson 1)
 The numbers 1119 are the sum of 10 ones and 1, 2, 3, 4, 5, 6, 7, 8, or 9 ones. (Lesson 4)
 We can count on from 10 by 1, 2, 3, 4, 5, 6, 7, 8, or 9 to reach the numbers 1119. (Lesson 7)
Prior Knowledge Needed:
 Counting to 100 by ones and tens; (Grade K, Unit 13; K.CC.A.2)
 Composing ten; (Grade K, Unit 12; K.OA.A.4)
Units on the Horizon:
 Understanding ten ones make a ten; (Grade 1, Unit 1)
 Exploring quantities to 99; (Grade 1, Unit 4)
Lessons

Lesson objective: Understand that the numbers 1119 are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones. Students bring prior knowledge that every number 1 to 9 has a partner such that the two numbers can be compose...

Lesson objective: Compose and decompose numbers from 11 to 19 into ten ones and some further ones. This lesson helps to build fluency with composing numbers 1119. Cups filled with counters and ten frames are used because they support students' understa...

Lesson objective: Decompose numbers from 11 to 19 into ten ones and some further ones. This lesson helps to build fluency with decomposing the numbers 11 to 19. Ten frames, counters and numeral cards is used here because it supports students' understand...

Lesson objective: Extend understanding that we can compose and decompose numbers from 11 to 19 into ten ones and some further ones. Students bring prior knowledge that the numbers 1119 are composed of ten ones and one, two, three, four, five, six, seve...

Lesson objective: Decompose the numbers 11 to 19 by finding the sum of 10 ones and 19 ones. This lesson helps to build fluency with decomposing teen numbers. Number bonds are used here because it supports the idea of decomposing teen numbers into ten o...

Lesson objective: Apply their knowledge that the numbers 1119 are the sum of 10 ones and 1, 2, 3, 4, 5, 6, 7, 8, or 9 ones. This lesson provides an opportunity for students to apply their knowledge and understanding of numbers 1119 to a mathematical s...

Lesson objective: Extend understanding that we can compose and decompose the numbers 1119 by starting with ten ones and counting on some further ones. Students bring prior knowledge that the numbers 1119 are the sum of ten ones and one, two, three, fo...

Lesson objective: Count on from 10 by 1, 2, 3, 4, 5, 6, 7, 8, or 9 to reach the numbers 1119. This lesson helps to build procedural skill with counting on from 10. The arithmetic rack is used here because the motion of pushing ten beads beads over at o...

Lesson objective: Compose the numbers 1119 by counting on from 10 by 1, 2, 3, 4, 5, 6, 7, 8, or 9. This lesson helps to build fluency with counting on from 10. Connecting cubes is used here because it supports students' understanding that teen numbers ...

Lesson objective: Solve problems by counting on from 10 to reach the numbers 1119. This lesson provides an opportunity for students to apply their knowledge and understanding of counting on from ten to reach the numbers 1119 to a reallife situation. ...