Lesson plan Grade 2 Math
Copperlake School's Faucet Fix-Up Cart: A Grade 2 Coin Lesson
A 45-minute grade 2 money lesson in which students count coins and make change to buy the small parts that stop a dripping school faucet.
Objectives
- Students will find the value of a group of coins and write it with the cent symbol.
- Students will add two part prices and subtract to find the change from a stated amount.
- Students will explain why a group with more coins is not always worth more money.
Vocabulary
Key words: coin, cent, change, total, washer, aerator
Teacher overview
A dripping faucet is usually fixed with parts that cost less than a dollar, which makes school plumbing repair a natural setting for grade 2 coin work. In this lesson the class shops from a supply cart in the town of Copperlake, where a rubber washer, a hose washer, an aerator, a spray nozzle, and a toilet flapper each carry a price tag in cents. The misconception to watch for is the belief that a handful with more coins is always worth more money, so a student who holds five pennies is convinced of having more than a classmate holding one quarter. Model the exchange directly with play coins rather than correcting the idea in words alone.
Procedure
Hook (5 min): Hold up a quarter in one hand and five pennies in the other and ask which hand holds more money. Take a quick vote and record the tally on chart paper without saying who is right. Tell students that the custodian at the school in the town of Copperlake keeps a fix-up cart, and that the class will decide what the cart can afford by the end of the lesson.
Direct instruction (10 min): Post the five price tags: rubber washer 15¢, hose washer 5¢, faucet aerator 60¢, spray nozzle 85¢, toilet flapper 95¢. Using play coins under a document camera, count out 60¢ for the aerator two different ways, first with two quarters and one dime, then with six dimes. Write both as 60¢ so students see that the same value has many coin arrangements. Show that 155¢ is also written $1.55, since problem 6 crosses a dollar. Return to the hook vote and settle it with the coins on screen.
Guided practice (12 min): Give each pair a cup of play coins. Call out three purchases in turn and have pairs build the exact amount and hold it up: 15 cents, 85 cents, and 90 cents. After the third one, poll the room with thumbs up or down on the question "Does a bigger pile always mean more money?" If fewer than three quarters of the class answers no, repeat the quarter-and-pennies comparison with a second pair of amounts before moving on.
Independent practice (13 min): Distribute the handout. Students work the six problems with play coins available on the table. Circulate and ask two students to explain how they found the change in problem 3 out loud, since making change from a stated amount is the step most students skip.
Closure (5 min): Students show their answer to handout problem 6 at the door and say whether the total is more or less than one dollar. Scan for students who wrote 155 cents but could not say that this is more than a dollar, and plan a short small-group review for them.
Student Handout
Suppose you are helping at the fix-up cart in the town of Copperlake. Here are the prices.
| Part | Price |
|---|---|
| Hose washer | 5¢ |
| Rubber washer | 15¢ |
| Faucet aerator | 60¢ |
| Spray nozzle | 85¢ |
| Toilet flapper | 95¢ |
Show your work with coins or with numbers. Write each answer with the cent symbol, like 20¢.
- A rubber washer costs 15 cents. A hose washer costs 5 cents. How much do both parts cost?
- Dev has 1 quarter, 2 dimes, and 1 nickel. How many cents does Dev have?
- A faucet aerator costs 60 cents. Rosa pays with 3 quarters. How much change does Rosa get back?
- A spray nozzle costs 85 cents. A hose washer costs 5 cents. How much more does the nozzle cost?
- The class has 100 cents to spend. They buy a rubber washer for 15 cents and an aerator for 60 cents. How many cents are left?
- A toilet flapper costs 95 cents. A faucet aerator costs 60 cents. How much do the two parts cost together?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: 20 cents. Add the two prices: 15 + 5 = 20 cents. Students may also count on from 15 by fives.
- Answer: 50 cents. One quarter is 25 cents, two dimes are 20 cents, and one nickel is 5 cents. 25 + 20 + 5 = 50 cents.
- Answer: 15 cents. Three quarters are 75 cents. Subtract the price: 75 - 60 = 15 cents. A student who answers 60 has stopped after finding the price instead of the change.
- Answer: 80 cents. This is a compare problem: 85 - 5 = 80 cents.
- Answer: 25 cents. First add the two prices: 15 + 60 = 75 cents. Then subtract from the money the class has: 100 - 75 = 25 cents.
- Answer: 155 cents. Add the two prices: 95 + 60 = 155 cents. Students who write it with a dollar sign should write $1.55, and either form is correct.
Differentiation
Support
Give these students a coin mat with the value printed under each coin picture, and limit them to problems 1, 2, and 4, which involve a single operation. Let them build every amount with play coins before writing anything, and accept a drawing of coins as a complete answer.
Extension
Ask students to find two different coin combinations that pay for the spray nozzle exactly, then write both combinations and explain which one uses fewer coins. Students who finish that can list every part on the cart that costs less than the aerator.
ELL supports
Pre-teach the part names with the objects themselves, since a washer and an aerator are small enough to pass around the room. Post a sentence frame for the closure: "The two parts cost ___ cents, which is more than one dollar." Pair the words "change" and "left" on the word wall, because problems 3 and 5 use them for the same idea.
Extensions
Set up a classroom store the following week with the same five parts from the town of Copperlake and their price list. Students take turns as the shopper and the clerk, and the clerk must count the change back out loud. Recording the sales in a simple two-column table gives the class a data set for a later bar graph lesson.