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Unit 9: Treasure Map Navigator Lesson 9-4 6.AT.11

Apply Two-Variable Relationships to Solve Problems

I can write an equation to represent the relationship between two variable quantities and use it to solve a real problem.

Speaking and writing goal: I can justify a recommendation using the words equation, solution, and at least.

What Your Child Is Learning

In this lesson, students practice how to write an equation to represent the relationship between two variable quantities and use it to solve a real problem. They learn to show their thinking with numbers, pictures, words, or a model. The goal is not just getting an answer. Students should be able to explain why the answer makes sense.

Why This Matters

Expressions and equations help students describe patterns and missing numbers. This matters for planning, budgeting, games, coding, and solving everyday questions step by step.

What It May Look Like In Class

Your child may use the interactive lesson, guided notes, examples from the board, partner talk, and short practice problems. They may be asked to solve, draw a model, label important numbers, and explain their reasoning in a sentence.

How You Can Help At Home

You do not need to teach a new method. Ask your child to read the problem out loud, circle the important numbers, and explain what they tried first. Helpful questions include: What do you know? What are you trying to find? Does your answer make sense?

Apoyo para familias en español

Qué está aprendiendo su hijo/a

En esta lección, su hijo/a practica usar letras, números y reglas para resolver problemas. Puede usar dibujos, números, palabras o modelos para mostrar su pensamiento. Lo más importante es que pueda explicar por qué su respuesta tiene sentido.

Por qué es importante

Las expresiones y ecuaciones ayudan a describir patrones y números desconocidos. Son útiles para planear, presupuestar y resolver problemas paso a paso.

Cómo puede ayudar en casa

No necesita ser experto/a en matemáticas. Pídale a su hijo/a que lea el problema en voz alta, marque los números importantes y explique su primer paso. Puede preguntar: ¿Qué sabes? ¿Qué necesitas encontrar? ¿Tu respuesta tiene sentido?

Key Vocabulary

solution solución

A value of the variable that makes an equation true.

Example: h = 400 is the solution of 2.5h = 1,000.

substitute sustituir

To replace a variable with a number so you can compute.

Example: Substitute 8 for h in 2.5h to get 20 cars per shift.

at least al menos

That amount or more — the smallest amount that still works.

Example: The student council must wash at least 42 cars to raise $500.

predict predecir

To make a reasonable guess about a future amount using information you already have.

Example: The council predicts about 35 cars this year because they washed 34 last year.

justify justificar

To explain WHY an answer or recommendation makes sense, using the mathematics.

Example: Justify accepting the order by showing 1,000 cars take about 2.5 weeks.

Try It Together

Pick one or two problems. Let your child explain the first step before opening the answer.

  1. Evaluate 3x + 2 when x = 4.
    Show answer

    14

  2. Solve x + 6 = 15.
    Show answer

    x = 9

  3. Write an expression for 5 more than a number n.
    Show answer

    n + 5

  4. Is y = 3 a solution to y + 4 = 7?
    Show answer

    Yes