Estimation

Designed by:  Betty Melvin, Denny Terrace Elementary

1) Core Curriculum Objective: Estimate, calculate, and justify whether an amount of money is enough to make a purchase. (3ME2-5)

Grade Level: Third       Subject: Math

2) Overview: The students will select items to buy from a store, being careful not to go over the amount they have to spend. The students will add up the cost of the items selected and estimate the total cost of their purchase.  The students will then count out the amount of money needed for payment and take the merchandise to the checkout stand. The students will give the merchandise to the cashier and pay the requested amount.

3) Focus Question:  Can we estimate the amount of money we will need to pay for our purchases without going over the amount?

4) Resources/Materials:  Assorted items found in a store.  Such as:

Games                                 Puzzles

Books                                  Pencils

Cars                                    Trucks

Hats                                     Handbags

Belts

Other resources/materials needed are:

 Price tags

Calculators

Order Forms

www.funbrain.com/cashreg/index.html

Pencils

Menus from the mall

Money (Play)

Money (Real)

5) Culminating Assessment:  Students will demonstrate their ability to estimate and calculate the cost of lunch.  Students will take a field trip to the mall where they will be allowed to purchase lunch.  The estimation rubric below will be used to asscss the students ablilities to correctly estimate and calculate the costs of their purchases.

6) Estimation Rubric

0                    No form completed

1                    Incomplete form

2                    Form completed, estimation incorrect

3                    Form completed, estimation correct

 7) Instructional Activities:

Activity One:  The teacher will set up products for students  to purchase.

(Ex:  Sally has $3.00.  She selects: 1 book @ .75 ,  1 puzzle @ $1.25 ,
3 pencils @ .25

Sally estimates her total purchase equals $2.75.  She is correct because:

.75 + 1.25 + .75 = 2.75

She also estimates her change will be .25.  She is correct because: 

3.00 – 2.75 = .25

The teacher will give the students $5.00 to purchase their items.  The students will need to count out the money for their purchase. The teacher will be the cashier. The student will go to the cashier and purchase their items. The student will tell the cashier how much change they will receive. The cashier will add up the cost of the items and accept the money. After each student has made a purchase, they will take a turn being the cashier.  As the cashier, they will make sure the students (purchasers) are receiving the correct change.  After all students have had the opportunity to purchase items and become the cashier they will return to their seats. Also, they will return the store items.   The teacher will ask the following question after the lesson, What happened when you did not give the cashier the correct amount of money?

Homework: Write a paragraph describing a setting in which you were not able to calculate the amount of a purchase and you received the incorrect amount of change.

Activity Two:  The teacher will review the results of the store activity from yesterday.  The teacher will divide the class into pairs.  The students will need to have computers turned on and connected to the Internet.  The teacher will have each group go to the website:

www.funbrain.com/cashreg/index.html

The students will complete the Change Maker Game using the AVER Key; the object is to get as much money in their bank as possible.  The students are to figure out how many of each coin they expect to get back when they pay for something. If they get the answer correct, the amount of change is added to their piggy bank. If the answer given is wrong, the correct amount of change will be subtracted from their piggy bank. The more money you have in the bank, the harder the questions will get.

The teacher will walk around the classroom making sure that students understand the Change Maker Game.  The teacher will provide help as needed.

Activity Three:  Students will take a field trip to the mall. They will be allowed to purchase lunch.  Prior to the field trip, the teacher will get menus from the mall.  The teacher will allow the students to choose what they want to purchase ahead of time. The teacher will give each student a form to show what they want to order.  The student will indicate on the form what they would like to order for lunch, estimate how much their lunch will cost, how much money they will be giving the teacher, as well as how much change they will receive back.  The teacher will determine whether the student’s form is calculated correctly.  The teacher will help the student make the necessary corrections.  The teacher will place the orders for lunch ahead of time.