Grade 3 Semester 1 Week 8: Using Bar Models: Addition and Subtraction
Topic: Using Bar Models:Addition and Subtraction
“I can” Statements
I can solve up to 2-step word problems involving addition and subtraction.
Common Core Standards
Solve two-step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.
Suggested Workbook Series
Math in Focus workbook (3A) Chapter 5 – Using Bar Models: Addition and Subtraction (pages 73 to 92)
Primary Mathematics workbook (Common Core Edition) (3A) Chapter 2 – Addition and Subtraction (pages 64 to 74)
Associate the terms ‘sum’ and ‘difference’ with the comparison model, e.g. ‘The sum of 35 and 60 is 95 and their difference is 25.’
Solve a variety of problems: 1-step word problems, 2-part word problems (1 step for each part), 2-step word problems and non-routine problems to become familiar with the problem-solving process.
Work in groups to create 2-step word problems involving addition and subtraction up to 4 digits for other groups to solve.