# T4T Changing Numbers (Lesson 2 of 6)

Lesson excerpt:

NC Mathematics Standards:

Extend and recognize patterns in the counting sequence.

NC.1.NBT.7 Read and write numerals, and represent a number of objects with a written numeral, to 100 20.

NC.1.NBT.1 Count to 150, starting at any number less than 150.

Standards for Mathematical Practice:

1.  Make sense of problems and persevere in solving them.

4.  Model with mathematics.

6.  Attend to precision.

Student Outcomes:

●     I can work with a partner to solve math problems.

●     I can count on from a given number within 100.

●     I can explain the process of solving a problem to my teacher and classmates.

Math Language:

·         Count, count on, next, ones, ten

Materials:

●     Bags (paper), Cube bags activity sheet, Twenty board, Multi-link (pop) cubes, Number cards, Pattern blocks, Ten Frames, Two-color counters

●     Gather materials

●     Prepare 15 cube bags. Each bag should have between 1 and 20 cubes in it.

Launch:

1. Introduce the word communication.

·         Ask:  What does the word communication mean to you?

·         Allow students to respond with their ideas. If you want you can record them.

·         Say: Mathematicians communicate their ideas and strategies with one another.

·         Explain: Many times mathematicians need to work together to solve problems.

·         Read the task to students:  There are 2 children in the park. Then 6 more children come to the park. How many students are now in the park?

·         Provide students with counters and ten frames to work on the task. Give students 3-5 minutes to work on the task with partners.

o   What strategies did you use to solve the task?

o   If we were going to draw a picture about how we solved the problem, what would our picture look like?

o   Students may say:

“I drew 2 circles and then drew 6 more circles.”

“I wrote the numbers 1, 2 and then the numbers 3, 4, 5, 6, 7, 8.”

·         Read the follow up task. There are 8 children in the park. Then 2 of them go home. How many children are now in the park?

·         Provide students with counters and ten frames to work on the task. Give students 3-5 minutes to work on the task with partners.

o   What strategies did you use to solve the task?

o   If we were going to draw a picture about how we solved the problem what would our picture look like?

o   Students may say:

“I drew 8 children and then crossed 2 of them out.”

“I wrote the numbers 1 to 8, then I crossed out 8 and 7.”

·         As you conclude this phase say:  It is important that mathematicians communicate to others about the strategies that they use.

Explore

1. Introduce Changing Numbers to students.

·         Have a student come to the front of the class to model the activity with you.

·         You and your partner are going to have a set of number cards, a ten frame, and counters.

·         Directions:

A student draws a number and builds that number on the ten frame. Example: A 4 on the card means 4 counters on the ten frame.

The partner then draws another card and then has to change the picture to match the new card. Example: A 7 on the card means you would add counters to the picture to get 7.

On the recording sheet the students fill in the chart. Example: Start number: 4, New number: 7. Change: I added 3 more.

Partners then talk to each other. We started with __. We changed it to __ by ______ .

The game continues.

1. Playing Changing Numbers

·         Allow students 10-12 minutes to work on the activity.

Discuss:

5.      Bring students together to discuss their strategies on the changing numbers activity.