A.2.1.1 Opener - A Main Dish and Some Side Dishes

Here are some letters and what they represent. All costs are in dollars.

  • m represents the cost of a main dish.
  • n represents the number of side dishes.
  • s represents the cost of a side dish.
  • t represents the total cost of a meal.
What does each equation mean in this situation? a. m = 7.50 b. m = s + 7.50 c. ns = 6 d. m + ns = t

Here are some questions to think about: What is an equation? What does it tell us?

Can equations contain only numbers?

Could this equation be true: m + 5 = t? How do you know?

When might the equation m + 5 = t be false?

One equation tells us that a main dish is $7.50. Another equation tells us that it is equal to the expression s + 7.50. Could both be true? Are they both appropriate for expressing the cost of a main dish?