← Day 3
UNIT 5 / 8 · LESSON 1 / 4 · 25 MINUTES

Translate before calculating

Name the unknown and write the relationship before touching the calculator.

01 / THE METHOD

Make it repeatable

  1. Define a variable with units.
  2. Translate “total,” “each,” “more than,” and “remaining” into operations.
  3. Solve the equation.
  4. Substitute back and answer in the requested units.
02 / WORKED EXAMPLE

Watch the method in action

A taxi charges $4 plus $2 per mile. The fare is $18. How many miles?
  1. Let m be miles.
  2. Write 4 + 2m = 18.
  3. Subtract 4 and divide by 2: m = 7.

Seven miles costs 4 + 2(7) = 18 dollars.

03 / QUICK CHECK

Try it yourself

What equation models the fare?

04 / PRACTISE AND CHECK

Apply the method to real questions

Start with guided questions and feedback. Then take a fresh independent set without hints. Reach at least 80% on that set to record this lesson.

Pass the quick check above to unlock practice.