Beacon Lesson Plan Library

Don't Eat the Crayons: Real-Life Multiplication

Susan Vinson

Description

Students use items which come in sets to look for real-life multiples and write multiplication problems. For example: a box of 24 crayons has 3 rows of 8 crayons, so the problem written would be 3 x 8 = 24. A candy bar: 2 rows of 4 segments (2 x 4 =8).

Objectives

The student explains and demonstrates the meaning of multiplication (for the repeated addition, array, and area models) using manipulatives, drawings, number sentences, and story problems.

The student solves real-world problems involving addition, subtraction, multiplication, and division of whole numbers using an appropriate method (for example, mental math, paper and pencil, concrete materials, calculator).

Materials

-FULL boxes of crayons (1 per student, or pair of students)
-Spare crayons
-Candy bars with segments (1 per student)
-Assorted items packaged in an array (colored pencils, sheets of stickers), enough for 2 per child
-Student worksheet
-Rubric overhead
-Overhead projector

Preparations

1. Make student copies of the worksheet. (Duplex)
2. Obtain crayons, candy bars, other items.
3. Make overhead of the student scoring rubric.

Procedures

1. Announce that you will be giving each child several items, one of which they may eat at the end of the activity. Hold up a box of crayons and ask them if they think this is the item to be eaten.

2. Affirm that those who suspected the crayons were not going to be eaten were correct, but tell them we will start with the crayons for the first project, but later have the edible item.

3. Ask them to raise their hands if they know how to multiply already. Then ask them if the box of crayons looks like a multiplication problem to them. Say- well, letís look at a box more closely. Remember that multiplication is a short way of adding, and we can use it only when we have equal sets of numbers.

4. Have a student pass out the crayon boxes, or have the children get out their own boxes. Supply full boxes or spare crayons for children who donít have a full set. Also pass out the student worksheet. Now model and have them count the number of rows and the number of crayons in each row. Ask- -How many rows? Do we have equal numbers of crayons in each row? Can we make a multiplication problem for the box of crayons?- Guide them to fill in the first set of blanks on the worksheet for the box of crayons.

5. Model the written multiplication problem on the board and have students contribute ideas as you write. Have students copy the problem on their paper.

6. Now pass out the candy bars. (Caution them not to eat them until directed to do so!). Remind them that they need to look for the number of rows and the number of pieces in each row. (They donít need to break the candy bar.) Now they should record their answers on the worksheet- filling in all the spaces for the second problem. Remind them that the word problem is a question, and should end with a question mark.

7. Ask students to share their answers. (They might first check with a partner to see if they have similar answers.) Ask them- -Is this making sense to you? Are there any questions about how to do this?- (Some students may have discovered the commutative property, so demonstrate to the group that 2 x 4 is the same as 4 x 2)

8. Using an overhead copy of the rubric, show the students what you will be looking for to see if they have mastered this concept.

9. Now allow the students to eat the candy while they complete the back of the worksheet with other items.

10. Collect the student work to be scored (problems 3 and 4) using the rubric to determine whether sufficient mastery has been achieved.

Assessments

This activity will formatively assess the studentís understanding of the meaning of multiplication using an array model and manipulatives to construct corresponding drawings, number sentences and story problems. Collect samples of student problem solving on paper of their experiences with real-life materials, and score with the teacher rubric.

Extensions

As an alternative assessment, the ESE or ESOL learner could orally explain, or demonstrate the concepts, or even use a computer-based, virtual manipulative program, like Math Keys to create their written response.

The Commutative property of multiplication would likely be discovered as they are working. Is the candy bar really 2 x 4 or 4 x 2? This could become a separate lesson, specifically creating both problems of each item.

This would make a great family homework project. Have the children look around their home or kitchen for other products that could illustrate multiplication, then draw or record a certain number to bring in and share with the class. (Eggs, 2 rows of 6 or 6 rows of 2!)

Web Links

Web supplement for Donít Eat the Crayons: Real-Life Multiplication
Clip Art from Discovery

Web supplement for Donít Eat the Crayons: Real-Life Multiplication
Rubrics

Return to the Beacon Lesson Plan Library.