Lesson 10 — Activity 1:

The 4-Step Method

Sweet Dreams Bakery sells apple, cherry, and pumpkin pies. Yesterday, they sold 24 pumpkin pies. The bakery sold 11 more apple pies than cherry pies, and 17 more cherry pies than pumpkin pies. Each pumpkin pie is cut into 19 slices. How many pies did Sweet Dreams Bakery sell in all yesterday?

two pies

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This is a word problem — it uses words to describe the problem! So, where do you start? What information is important and what is extra? What operation are you going to use to answer this question?

Hang on, and we'll show you how to solve it and other word problems!

In Math 9-4, you learned about the 4-Step Method for answering word problems. In this lesson, you will review the steps and then answer the word problem above.

Step 1: Understand the Problem

To understand a word problem, you need to be able to answer some questions.

What information is given?
What are you asked to find?
Does the question need an exact or approximate answer?

Step 2:Think of a Plan

The key words in a problem and the important information given will help you develop a plan for solving problems. You may decide to:

look for patterns
draw a picture or use manipulatives
make the problem simpler
practise using Guess and Check
work backwards
organize information

Step 3: Carry out the Plan

You can do the following to carry out your plan.

Solve the problem using a pencil and paper, manipulatives, a calculator, a computer, or by using another strategy that you identified in your plan.
Remember to always state the solution to the problem in a statement.

Step 4: Look Back and Verify

You can choose one or more of the following strategies to check your answer for reasonableness.

Use the information and/or numbers in the problem to estimate a solution. Then compare your answer to this estimate to help you determine if your answer is reasonable.
Check that decimals are placed correctly.
Use a calculator.
Use the opposite operation (subtract if you added, divide if you multiplied, etc.).
Compare your answer with others.

Look at this problem:

Sweet Dreams Bakery sells apple, cherry, and pumpkin pies. Yesterday, they sold 24 pumpkin pies. The bakery sold 11 more apple pies than cherry pies, and 17 more cherry pies than pumpkin pies. Each pumpkin pie is cut into 19 slices. How many pies did Sweet Dreams Bakery sell in all yesterday?

Click on the tabs to follow the steps.

In this problem, we are given quite a bit of information. Let's identify which information is most important and what you are asked to find.

Sweet Dreams Bakery sells apple, cherry, and pumpkin pies. Yesterday, they sold 24 pumpkin pies. The bakery sold 11 more apple pies than cherry pies, and 17 more cherry pies than pumpkin pies. Each pumpkin pie is cut into 19 slices. How many pies did Sweet Dreams Bakery sell in all yesterday?

The most important information and what you are asked to find has been highlighted above. This problem also has information that will not help us to solve the problem. For example, the problem tells us that each pumpkin pie is cut into 19 slices. This information is not important to us, as all we need to find out about is HOW MANY PIES (whole pies, not slices) did they sell. Therefore, we can ignore this information. So now we understand the problem!

There are many strategies you can use in this step. For this problem, it would be best to make it simpler. That is, we must first figure out how many pies of each kind were sold, and then determine how many pies were sold altogether.

Now we will begin to solve our equation.

What do we know?

They sold 24 pumpkin pies.
The sold 11 more apple pies than cherry pies.
They sold 17 more cherry pies than pumpkin pies.

Therefore, if they sold 17 more cherry pies than pumpkin pies (17 + 24), they sold 41 cherry pies.

If they sold 11 more apple pies than cherry pies (11+ 41), they sold 52 apple pies.

So, we know now that they sold 24 pumpkin pies, 41 cherry pies, and 52 apple pies.

Now, our equation would look like this:

24 + 41+ 52 = 117

Sweet Dreams Bakery sold 117 pies in all yesterday.

Remember to always state the solution to the problem in a statement (or sentence answer).

This final step is very important. Does the answer make sense? In the problem, we wanted to know how many pies were sold yesterday. Our answer is 117, which makes sense if they sold different amounts for each of the 3 pies (24 pumpkin, 41 cherry, and 52 apple). Does it make sense that a bakery might sell 117 pies in one day? Yes, it does — so our answer of 117 pies checks out!