Multiplying Money

Designed by: Kristin Reinfurt, Rosewood Elementary

Grade Level: Three       Subject: Mathematics

Core Curriculum: Multiply money written in decimal form by one-digit factors in real world problems. (3ME2-4)

Overview: Students will use movie ticket prices and zoo admission prices to practice multiplying money amounts by single digit numbers of people. They will each use the internet to find the admission prices for several amusement parks surrounding Columbia. Then they will multiply the admission prices by a number of children and adults to determine the total cost to visit each place.

Focus Question: How can we multiply amounts of money to find a total cost?

Time Frame: Two fifty minute class periods

Resources:

Pencil and notebook paper for each student

Chart paper

Enough copies of the movie listings page from the newspaper for each group of four

Computer lab

Computer with internet access

AverKeys (if available)

www.riverbanks.org

www.discoveryplace.org

www.carowinds.com

www.scaquarium.org

www.sixflags.com/georgia

www.myrtlewaves.com

Culminating Assessment: Students will individually use a computer to find the admission prices for children and adults at three amusement parks. They will then multiply the prices by a chosen number (less than ten) of children and adults. The teacher will assess the multiplication process using the following rubric.

Instructional Activities:

Activity One: Each student will need a piece of notebook paper and a pencil. Divide students into groups of four. Hand each group the page from any recent newspaper that shows the movie listings and admission prices. Ask the groups to discuss how they could figure out how much it would cost their group to go to a movie. Discuss the different ways as a class (add the price four times or multiply the price by four). Have the group use addition to find out the total cost. Remind them about lining up the decimal, including the dollar sign, etc.

Tell them that today they are going to learn how to multiply the price to find the total cost. On the board or overhead, create a problem from the movie page to demonstrate the process of multiplying money by a single number. Point out the similarity to multiplying a three-digit number by a one-digit number, but the difference is that it is a money amount with a decimal point. Afterwards have the class verbalize the steps in the process for a class chart:

1. Line up the numbers (make sure the money amount is written correctly, the money amount should be the top number) 

2. Multiply the ones number, then tens, then hundreds - making sure to show when you carry a number to another column 

3. To figure out how to make your answer a dollar amount, count how many spaces the decimal point is over to the left in the dollar amount. Then count over that many spaces in your answer. (When multiplying by a single digit, this will be two spaces over which is how students should be used to writing money amounts already.) 

4. Add a decimal point and dollar sign to your answer. 

5. Check your work to make sure your answer makes sense.

Have each group work together to find out the total cost of the group going to a movie using multiplication. Monitor groups as they work to check for comprehension of the process. Check groups' totals and answer any questions.

Allow for more practice with the groups finding different group costs such as for six children going to the movie, four adults seeing a movie instead of four children, a group seeing the twilight movie which is cheaper, or seeing a movie at the $1.50 theater. Have each student write and solve the problems themselves, but encourage them to check their answers with the group and self-check that they are following the steps correctly for multiplying the amounts.

Using AverKeys and a TV screen (or a computer monitor), show the web site for Riverbanks Zoo www.riverbanks.org Model how to find the admission prices by clicking on information and then admission prices. Discuss that prices are also called rates sometimes. On a piece of chart paper, model a format to organize the information that you are going to ask them to calculate. Show them how to do the calculations using the chart/table. A completed one might look like this:

Destination: Riverbanks Zoo

Ask them to use their paper to multiply the cost for four children to get into the zoo. Have them multiply to find the cost for four adults. Check answers together. Review process and correct errors as needed. Ask them to find the total cost for the group of eight to get into the zoo.

Explain that they will be doing some research on the internet tomorrow to calculate some total costs. Show the culminating assessment. Explain that they will be assessed based on whether they correctly used the process to multiply at least four money amounts correctly and for having the correct answers.

Homework: Provide copies of menus or sale pages with prices from a newspaper and have students create situations to calculate total costs using multiplication. Have students choose one of the situations to publish in a class book called Multiplying Money. An example: (write the words) Yesterday my sister and I went to the sale at JCPenney. We saw that earrings were on sale for $3.99. We bought five pairs together and it only cost us $19.95. (Illustrate this story, write the equation, and show how it was solved.)

Activity Two: Introduce the assignment by asking students to imagine that they get to have a really special birthday party this year where they get to take the party on a trip for the day. They will each get to choose where to take the party, but to be nice to their parents, they need to do some research and find the least expensive option.

There are a couple of rules that they need to keep in mind for their party: 1. They may invite nine children at the most. 2. They must have at least two adults go with them. 3. They must compute the cost for all of the kids/adults using multiplication which will be assessed as the culminating assessment.

Before going to the computer lab, have each student get out a piece of paper and pencil. They need to first write down how many adults are going to go and how many children they want to come. Review how to make an organized list/table to record their information and complete their calculations.

In the computer lab, post the above web sites for amusement parks/fun places within a couple of hours of Columbia. Tell students that their job is to visit the web sites of three of these places and find the admission prices/rates for a one-day visit for children and for adults just like we did for the zoo yesterday. They are to record the prices in the table on their paper. When they have recorded the admission prices from all three places, they are to multiply the cost by the number of children at the party to get a total cost for the children. Then they are to do the same with the adults. Then they are to add the children cost and adult cost to find the total cost for bringing the birthday party to that place. Remind them that they are being assessed for completing the multiplication process correctly and also for having the answers correct.

When they have completed their calculations, they are to figure out which place is the least expensive and write down where they will be going for the birthday party.

Extension: Have students write up a bill for the place that they chose and give it to their parents. They could also create an invitation that includes some of the information they located at the web sites.