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Lesson Seeds: The lesson seeds are ideas for the indicator/objective that can be used to build a lesson. Lesson seeds are not meant to be all-inclusive, nor are they substitutes for instruction.

Standard 1.0 Knowledge of Algebra, Patterns, and Functions

Topic B. Expressions, Equations, and Inequalities

Indicator 1. Write and identify expressions

Objective a. Represent numeric quantities using operational symbols (+, -, ×, ÷)

Assessment limit: Use operational symbols (+ or -) and whole numbers (0 – 50)

Materials needed

Brown lunch bag, index cards numbered 0-50

Activities

Activity 1: Draw Two Cards
Working in pairs, students can take turns drawing a number card from the bag. Pairs should then write an expression using the two numbers they drew and either addition or subtraction. They should also create a situation that would represent the expression. For example, if they drew the numbers 25 and 5, an expression might be 25 + 5. The situation that might accompany the expression might be, "I had a quarter and I found a nickel". If the expression is 45 - 15, the situation might be, "I had 45 baseball cards and I gave 15 to my brother".

Activity 2: Draw One Card
Working in pairs, students draw one number card and brainstorm ways to get that number.

For example, some possible ways to get 24 with addition and subtraction:

20 + 4
30 - 6
12 + 12
34 - 10

Students might also come up with ways to get 24 using multiplication and division. For example:

12 × 2
6 × 4
48 ÷ 2

Then have students see that 20 + 4 and 30 - 6 are equivalent expressions, so they could be written as a number sentence: 20 + 4 = 30 - 6

Teachers may set restrictions on the number of numbers and types of operations in the expression. For example, "Make the number you draw by adding three numbers."

McIntosh, Alistair, et al., Number Sense, Grades 3-4, Dale Seymour Publications, 1997.
/instruction/lessons/mathematics/grade3/xml/1B1a.xml
Resources for Objective 1.B.1.a:
LESSON SEEDS | Sample Assessments |