# Appendix A: Example Chinese G1 Lesson Plan about Fact Families (Additive Inverse)

## Addition with the Sum of 8 and Subtraction from 8

G1 Math textbook (vl), Jiang Su Education Press Edition, pp. 54—55, Worked example and the “Think then practice” tasks.

Brief Lesson Analysis

The goal of “addition with the sum of 8 and the related subtraction” is to help students obtain a preliminary understanding of the connection between addition and subtraction through learning “one picture with four number sentences” (—ЦЦЩй;), which is based on students’ prior learning of “one picture with two number sentences” (—[Ц ~ j£). The teacher needs to make a transition from “one picture with two number sentences” to “one picture with four number sentences” in order to help the students smoothly understand the four number sentences’ relations to the real-world situation. The teacher also needs to guide the students to: examine all four number sentences in relation to the picture, understand the connection between addition and subtraction based on the real-world meaning, and infer the result of one number sentence from the other. This lesson includes plenty of content, so the practice problem design needs to be diverse in form and catered to the students’ interests in order to engage them in active participation. When presenting the real-world problem, the teacher should ask the students to talk about their meaning of the picture, sense the real-world situation, and solve the problem using mathematic knowledge and real-life experience.

Teaching Objectives

• 1 Students will be able to (SWBAT) experience the process of posing math problems based on real-world contexts in order to solve the proposed problems and learn how to compute addition problems with the sum of 8 and the related subtraction problems.
• 2 SWBAT write four number sentences based on one picture, preliminarily feel the connection between addition and subtraction, and develop comparison and concept-association ability, creative thinking, and mathematical flexibility.
• 3 SWBAT sense the connection between math and real life and gradually develop the ability to think mathematically and solve simple, real- world problems.
• 4 SWBAT be more interested and engaged in math activities through the process of communication and cooperative learning.

Important Points of Teaching

Through observation, thinking, collaboration, and communication activities, students will grasp the computational methods for addition with the sum of 8 as well as the related subtraction. They will also be able to solve simple problems based on real-world connections.

Difficult Points of Teaching

Understand the meaning of number sentences and know the relationship between addition and subtraction.

Teaching Material

Multimedia courseware (PPT), and number cards Teaching Process

## I Introduction to Activate Interests

(Showing the swimming pool picture on the screen) Look, there is a group of children in the swimming pool. Some of them are swimming in water, and some of them are resting near the edge of the pool. Please count and find out: how many children are swimming and how many children arc resting?

## II New Lesson

### Self-exploration of the new knowledge

• 1 Can you ask an addition question according to this information?
• 2 Anticipated student answer: How many children arc there together? How do you write a number sentence to solve it? (Teacher writes on the board when appropriate)
• 5 + 3 = 8 3 + 5 = 8
• • Pick a number sentence, and talk about how you computed it. What does this number sentence mean?
• • Guide the students to observe the two number sentences. What did you find? (First share in small groups, and then share with the whole class)

о (Exchanging the position of two addends besides the addition sign, the sum won’t change.)

• • According to this picture, can you pose a problem that can be solved by subtraction? How do you write the number sentence? о Teacher writes on the board based on students’ answers 8-3 = 5 8-5 = 3
• • Pick a number sentence and talk about how you computed it. What does this number sentence mean?
• • Observe these two number sentences. What have you found? (Subtract one particular number from the total, and you will get the other number; Subtract the other number from the total, and you will get that particular number.)
• 3 Guide students to observe again. How many number sentences did we list for one picture?

Look at these four number sentences. What are the connections among them?

• (First share in small groups, and then share with the whole class) (Read the lesson title) This is what we have learned today: Addition with the sum of 8 and subtraction from 8.
• 4 “Give a try” #1

I find that two of the children in the group haven’t learned how to swim, do you know who they are? (Ask a student to point it out, and circle on the screen the two children with swim rings)

® Students observe and share their understanding about the meaning of the picture, and the teacher guides the students to express the meaning completely: There are two children with swim rings, and six children without swim rings. The total number of children is 8.

© Can you write two addition and two subtraction number sentences? (Students finish it on the worksheet)

© Share and evaluate: Talk about the meaning of the number sentences and how you computed them.

5 “Give a try” #2

Let’s look at the picture again carefully. How many children are wearing swimming caps, and how many aren’t? (Circle the one child that is wearing a swimming cap on the screen)

® Students observe and share their understanding about the meaning of the picture, and the teacher guides the students to express the meaning completely: There is one child wearing a swimming cap, and seven who are not. The total number of children is 8.

© Can you write four number sentences according to the picture? (Students finish it on the worksheet)

© Share and evaluate: Talk about the meaning of the number sentences and how you computed them.

### Reinforcement, Application, and Extension

1 “Think then practice” #1. We did a good job writing three groups of addition and subtraction equations based on the different information we saw in the swimming pool picture. Besides swimming, ball games are also our favorite. Please carefully count these footballs and vol- leyballs and then fill in the number sentences. (Students will observe the picture and write number sentences according to the picture that is projected through the PPT.)

Share and evaluate: Explain the meaning of number sentences according to the scenarios. And think about why we can only write two number sentences from this scenario.

2 Game: To test how well the students have learned the concept, Mr. Bear has set up a game called “Lucky three rounds.” Who is ready for the challenge?

Before the game, let’s do some warm-up (Finger Exercise).

Round one—“Pair up” (“Think then practice” #2)

• • Which of the two number cards add up to 8? (Model the game—I played 1, and I played 7, 1+7 = 8,7+1 = 8)
• • Cooperate with your deskmate and find out how many groups of cards add up to 8—find as many as you can.

® Students play the cards with their deskmates. Ask the students to demonstrate in front of the class.

Round two—“Merry-go-round” (“Think then practice” #3)

® Observe the picture carefully, and figure out what this question asks.