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### Overview

In third grade, students will solve two-step word problems using addition, subtraction, multiplication, and division. For example: There were ten adults and five children at the movies. Each adult ticket costs \$8.00 and each child ticket costs \$3.00. What is the total cost of all the tickets? The video demonstrates how to solve this problem.

### MA19.3.8

Determine and justify solutions for two-step word problems using the four operations and write an equation with a letter standing for the unknown quantity. Determine reasonableness of answers using number sense, context, mental computation, and estimation strategies including rounding.

## UP:MA19.3.8

### Vocabulary

• Unknown quantity
• Mental computation
• Estimation
• Variable
• Reasonableness
• Rounding
• Expression
• Equation

### Knowledge

Students know:
• Characteristics of addition, subtraction, multiplication, and division.
• Strategies for addition, subtraction, multiplication, and division.
• Strategies for mental computation and estimating sums, differences, products, and quotients.

### Skills

Students are able to:
• Use a variety of strategies to solve two-step word problems involving all four operations.
• Write an equation to represent the problem context, and use a symbol for the unknown quantity.
• Justify strategy and solutions using mathematical vocabulary.
• Determine and justify reasonableness of solutions using mental computation strategies and estimation strategies.

### Understanding

Students understand that:
• Mathematical problems can be solved using a variety of strategies, models, and representations.
• Contextual situations represented by multiplication and division.
• Reasonableness of solutions can be evaluated by using estimation strategies.

Audio/Video

### Resource Provider

PBS
Accessibility