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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.

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.

### Unpacked Content

## UP:MA19.3.8

### Vocabulary

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

### Knowledge

- 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

- 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

- 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.