Lesson: Total Cost: Identify the Number Sentence

Tara Smith E.l. Haynes Pcs Washington, DC
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Lesson Objective

SWBAT identify the number sentence of the total cost of items purchased.

Lesson Plan

Materials Needed: DN Worksheet, Chart with sample problems and steps, white board, dry erase markers, IND Practice Worksheet.
Vocabulary: unit cost, total cost, relevant, and irrelevant.

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Do Now (2 - 3 min): The teacher passes out the DN worksheet, which is a quick multiplication and division fact drill.

Opening (2 -3 min): Teacher opens by reviewing the answers to the DN. The teacher then states the objective, “Yesterday we learned about proportional relationships on a scale. Today, we are going to begin learning about unit costs and total cost. By the end of the lesson, you identify the number sentence needed to solve for the total items purchased.”

Direct Instruction/Guided Practice (15 - 20 min): Teacher explains, “By a show of hands, how many of you have gone to the store with someone in your family before? Maybe the grocery store? Maybe the mall? The shoe store? [Students all raise their hands]. Great, then you will all be able to picture this in your head; picture the following:

You walk into Footlocker and Air Jordan’s are on sale for are \$25.99. They have two color sets and you want 2 pair. How do you figure out what the total cost will be?

This is what we will be working on today, so not only can it help you when you are asking Mom, dad, or your Auntie to get you two pairs of fresh shoes, but it can help you reach your goal on the DC-CAS. Ok, so the first step to solving a problem like this is to figure out what information is relevant and irrelevant. Then you need to set up a number sentence. That is where we will be stopping today, because we have to be masters at this. Questions focusing just on the number sentences are all over the DC-CAS.” The teacher writes the following on the board/chart next to the word problem.

Step 1: What problem does the question want you to answer?
Intended answer for this problem: How much 2 pair of Jordan’s cost?
Step 2: Relevant and Irrelevant Information
Intended answer for this problem: Relevant: Jordan’s \$25.99 / 2 pairs. Irrelevant: Footlocker / on sale.
Step 3: Set up the number sentence
Intended answer for this problem: \$25.99 +\$25.99 =   -or-  2(\$25.99) =

Then the teacher continues, “Ok, so what problem are we trying to solve here? [Use intended answer language]. The Air Jordan’s are considered the unit in this problem, because we know how much a single pair of the Jordan’s cost. Now, what information do we need to solve that? What is the relevant information here? Let’s think back to three days ago, when we were focusing on relevant and irrelevant information. [Use intended answer language]. Alright, now that we have our two pieces of information to solve we need to set up our number sentence. To set up our number sentence we need to know what operation we should use. There are two operations we could set up this number sentence. We could set it up using addition, or we could set it up using multiplication. Watch as a write both of them out.  Now let’s practice one together before you show off what you learned.

Your mom and your sister went to the shoe store with you, and your sister spotted a Claire’s Accessories across from the Footlocker. There is a sale sign in the window reading: ALL earrings \$3.99. Your sister begs your mom to go look at the earrings.  There are 20 different styles of earrings. Your sister picks our 4 pairs that she wants. How much will the total cost be?

Step 1: What problem does the question want you to answer?
Intended answer for this problem: How much are 4 pairs of earrings?
Step 2: Relevant and Irrelevant Information
Intended answer for this problem: Relevant: earrings are \$3.99, she wants 4 pairs. Irrelevant: Claire’s, whose there, 20 styles
Step 3: Set up the number sentence
Intended answer for this problem: \$3.99 + \$3.99 + \$3.99 + \$3.99=   -or – 4(\$3.99) =

Independent (10 min): The teacher hands out the IND worksheet, which mimics Guided Practice. Students are asked to complete the worksheet independently and turn it in.

Closing (2-3 min): Teacher calls the attention of the students back toward the front of the class to quickly review the answers to the Independent Practice worksheet/ ask what we learned about.

Lesson Resources

 IND Lesson 4 sentence   Classwork 234 DN Lesson 4   Starter / Do Now 191