Virginia SOL 5.PFA.2

5.PFA.2 is a Standards of Learning standard. These are the knowledge and skills expectations under it.

• 5.PFA.2.a

  Describe the concept of a variable (presented as a box, letter, or other symbol) as a representation of an unknown quantity.

• 5.PFA.2.b

  Write an equation (with a single variable that represents an unknown quantity and one operation) from a contextual situation, using addition, subtraction, multi...

• 5.PFA.2.c

  Use an expression with a variable to represent a given verbal expression involving one operation (e.g., “5 more than a number” can be represented by y + 5).

• 5.PFA.2.d

  Create and write a word problem to match a given equation with a single variable and one operation.

01

What Students Need to Do

Students use a symbol to stand for an amount they do not know. They write one-operation expressions and equations from phrases and short situations. They also create a word problem that fits a given equation.

02

What Mastery Looks Like

Students explain what the variable represents and use a box, letter, or symbol correctly. They translate a one-step situation or phrase into an accurate expression or equation. They also write a sensible story that matches a given equation.

03

Common Misconceptions

Students may think a variable always stands for the same number or must be written as a letter. They may reverse subtraction or division, such as writing 12 − x for “12 less than x.” They may also confuse an expression, which has no equals sign, with an equation.

04

How to Assess It

Use this exit ticket: “Mia had some stickers, bought 8 more, and now has 23. Define a variable, write an equation, and solve.” Then ask students to write a matching story for 6 × n = 30.

1. 01

   Hide counters under a cup, show additional counters and the total, then have students model the hidden amount with a variable equation.

2. 02

   Ask students to explain how “9 less than a number” differs from “9 minus a number,” using expressions and sample values.

3. 03

   Give pairs cards with phrases, expressions, equations, and word problems to sort into matching sets, then check each set by solving.

4. 04

   Use a classroom snack budget, with one unknown price or quantity, and have students write a one-operation equation from the receipt.

• 7.CE.1

  The student will estimate, solve, and justify solutions to multistep contextual problems involving operations with rational numbers.

• 4.MG.2

  The student will solve single-step and multistep contextual problems involving elapsed time (limited to hours and minutes within a 12-hour period).

• 5.PS.2

  The student will solve contextual problems using measures of center and the range. 

• 8.CE.1

  The student will estimate and apply proportional reasoning and computational procedures to solve contextual problems.