Decomposing money - math grade 2 - lesson 62

Math4u grade 2 second term

ماث فور يو جريد 2 

math grade 2 second term

Mathematics Teacher`s Guide primary 2

Math primary 2 second term lesson 62

Note to the Teacher: ask students to identify any patterns they observe as they work with money. Also, consider setting up a math center where students can practice composing and decomposing banknotes to find different ways to create given totals. Students should record and post their work in the center and be encouraged to share and compare their thinking with others.

1. TEACHER SAY: Turn and tell your Shoulder Partner one thing you learned yesterday about money.

STUDENTS DO: Tell their Shoulder Partner one thing they learned about money.

TEACHER DO: Select two or three pairs to share their thoughts as a review.

STUDENTS DO: Selected students share their thoughts with the class.

2. TEACHER SAY: Do you remember yesterday I said I was going to the store to purchase some fruit? Well, when I got to the store, the fruit cost 5 LE all together. My problem was, I did not have a 5 LE banknote. I had six 1 LE notes and one 10 LE note, but no 5 LE notes. So how could I pay for my fruit? I am going to give you some Think Time to find a strategy to solve my problem. Share your thinking with your Shoulder Partner. When you are ready, raise your hand.

STUDENTS DO: Use Think Time to think of a strategy for solving the problem. Share thinking with their Shoulder Partner. Raise hand when they are ready.

TEACHER DO: Allow students time to think. Wait for most hands to be raised and then select a few students to answer.

STUDENTS DO: Selected students share their ideas.

TEACHER DO: Confirm appropriate strategies. Correct students’ major misconceptions. Since they are just learning about money, it is not necessary to correct all misconceptions, just those that could limit their learning later.

TEACHER SAY: I heard some of you say we can add different banknotes together to come up with 5 LE. When we have a larger number, we can decompose it into a set of smaller numbers. Let’s look at my problem.

Note to the Teacher: Students may also say, “use a larger banknote and get change.” This is another important (and accurate) decomposition strategy.

TEACHER DO: Hand out or have students take out the sets of banknotes. Draw one 5 LE note on the board:

TEACHER SAY: My fruit cost 5 LE. Using your banknotes, find a way to make 5 LE without using the 5 LE note. When you have found a way, I want you to pop up.

STUDENTS DO: Use banknotes to find a way to make 5 LE without using the 5 LE banknote. Pop up when they have found an answer.

TEACHER DO: Have students sit. Use Calling Sticks to select a student to share an answer.

STUDENTS DO: Selected student shares their answer.

TEACHER SAY: Yes, I could have used five 1 LE notes to pay for my fruit because five 1 LE notes is equal to one 5 LE note.

TEACHER DO: On the board next to your drawing of the 5 LE note, write an = sign and then draw five 1 LE banknotes. See the example below.
TEACHER SAY: Great work, class. Let’s try another one.

TEACHER DO: Draw one 10 LE note on the board.

TEACHER SAY: Use your banknotes to create 10 LE without using the 10 LE note. Pop up when you have an answer.

STUDENTS DO: Use banknotes to find a way to make 10 LE without using the 10 LE note. Pop up when they have found an answer.

TEACHER DO: Use Calling Sticks to select a student to share an answer.

STUDENTS DO: Selected student shares an answer.

TEACHER DO: Draw the student’s answer on the board (if it is correct). If it is not correct, ask the student to identify their error. Allow the student to ask friends for help. Once you have one correct answer on the board, move on.

TEACHER SAY: Raise your hand if you came up with a different way to make 10 LE using your banknotes.

STUDENTS DO: Raise hand to volunteer. Selected student shares a different answer.

TEACHER SAY: That is right. There are two ways we can make 10 LE using the banknotes you have in your set.

TEACHER DO: Draw the second method on the board (both methods shown below). Remember, students only have five 1 LE notes, so they are unable to make a set of ten 1 LE notes.

3. TEACHER SAY: Take out your Mathematics Student Book and turn to page Lesson 62: Apply.

STUDENTS DO: Take out book and turn to page Lesson 62: Apply.

TEACHER SAY: You are going to play a game to practice making some other amounts of money. The game is called The Banker.I will put you in groups of three. You will take turns so that each of you will be the Banker one time. The Banker will choose one amount: 20 LE, 50 LE, or 100 LE. The other two students will find a way to create that amount using their banknotes. You may combine your sets of banknotes to solve the problem. Once you find a way to make the amount of money given by the Banker, draw it in your student book, just as I did on the board.

TEACHER DO: Help students form groups of three using Count Off.

STUDENTS DO: Count Off to form small groups.

TEACHER SAY: Find a place to sit and work together. You need your student book, your set of banknotes, and your pencil. Once you are seated together, begin playing the game.

STUDENTS DO: Find a spot to sit with their group. Take student book and banknotes. Play

The Banker in groups and draw answers in their book.

Note to the Teacher: If students finish early, challenge them to find another way to make the 20, 50, and 100 LE quantities.

TEACHER DO: Walk around the room, observing students as they work and offering help as needed. Take note of students who may be struggling with identifying banknotes or counting money. After about 10 minutes, use an Attention Getting Signal.

TEACHER SAY: If you combined your banknotes, separate them into individual sets again. Keep your student book open but go back to your seat with your book and your banknotes.

STUDENTS DO: Return to desk with student book and banknotes.

Note to the Teacher: Today students found multiple ways to create 5, 10, 20, 50, and 100 LE amounts using their banknotes. Students reflect on their learning by comparing their combinations with their Shoulder Partner’s combinations. They examine how their combinations are alike and different and
discuss whether there are any other ways to create the amounts.

1. TEACHER SAY: As we reflect today, I would like you to compare your banknote combinations with your Shoulder Partner’s combinations. Compare the two sets for each amount. Are they the same? Are they different? Is there another way to make the amount? Discuss with your partner.

STUDENTS DO: Compare banknote combinations with their Shoulder Partner. Discuss alternate combinations for different amounts of money.

TEACHER SAY: Great work today, class. You may put your book and set of banknotes away. We will use them again in our next math lesson.

STUDENTS DO: Put away student book and sets of banknotes.