SWBAT add up the cost of supplies used. SWBAT use coins to pay for a total amount.

Today your students will figure out the total cost of each creature built in the previous day's lesson.

5 minutes

I start by having the students gather in a circle around the whiteboard easel. I want to spend a few minutes reviewing the greater than and less than symbols. As the year ends, this will be a focus on some of my end of year screening based on the data that I have seen for my class. It has been a while since we have specifically focused on this concept, so I will use this warm up time to review the concept. In this situation, the students are comparing two two-digit numbers and recording the results of comparisons with the symbols >, =, and < (CCSS.MATH.CONTENT.1.NBT.B.3).

I start by writing each symbol on the board (see Warm Up Activity).

*"Who could tell me what this symbols means (>)? What about this one (<)? What about this (=)? I am going to write and empty expression ( __ > __). Who can tell me a number that should go in the first blank and a number that can go on the second blank?"*

**I continue this for a few more examples. Again, you can see Warm Up Activity for the expressions that I used.**

15 minutes

Advanced Preparation: You will need to make enough copies of Finding the Cost for each student to use at least two sheets each.

*"Yesterday, each of you created a creature of your own. Today, you will work with a partner and use the price sheet to figure out the total cost of each creature built. You will need to figure out the cost by adding each item used and then represent the coins that you would use to make that amount."*

I will model how to do this with a creature that I have already made. If you would like an explanation of how to make the creatures, click on this link.

This activity will ask students to add three or more numbers to find a total and use symbols to represent coins used to equal a total. This meets the CCSS of having students relate counting to addition (CCSS.MATH.CONTENT.1.OA.C.5) and representing a situation symbolically through the use of coin symbols (CCSS.MATH.PRACTICE.MP2).

40 minutes

The students will work in teams to complete the Finding the Cost Activity. They should work on this task first, and if they finish early they can play Race to 100 (This game was introduced in a previous lesson. I have included the recording sheet, Race to $1.00, for you to print and use).

I included a few Examples of Student Work work from the Finding the Cost Activity. The first example demonstrates how a student in combining numbers to find the total. As I am circulating, this is what I am looking for to use as an example for the Lesson Wrap Up. The second example has some errors in the students representation of the equation but does have the correct coins. This is a student that understands the concept but may need a quick review about checking work. I have also included a video, Finding the Cost, that captures two students working together to find the cost of a creature. Listen to the discourse that the students have during this clip and the sharing of ideas that happens.

10 minutes

To end this lesson, I call the students back to the carpet.

"I noticed that many of you were having to add more than two numbers together today. Some of you were starting with one number and then counting on. Some of you were making combinations of ten and then adding some more."

I then ask them to model who they would solve the problem on End of Lesson Discussion. I had also included a video, Adding More Than Two Numbers, that captures this conversation.

If you look at the bottom of the right hand corner of End of Lesson Discussion, you will see a group of numbers that is connected by several equal signs. Students will tend to keep adding on the next addend to their equation and then add it and write the new total. By writing an equation this way, like the one on the poster, students are actually recording the equation incorrectly. It is important to explain this error now and help students record their work in a correct way with and appropriate equation.

5 minutes

I will ask the students to meet me on the carpet and hand out their sheet for today's Mad Minute exercise. This routine was introduced in a previous lesson. Please check out the link to get a full overview of this routine.

I want to really focus on fact fluency and build upon the students ability to solve within ten fluently (CCSS.MATH.CONTENT.1.OA.C.6). I am going to use the Mad Minute Routine. This is a very "old school" routine, but I truly feel students need practice in performing task for fluency in a timed fashion. Students need to obtain fact fluency in order to have success with multiplicative reasoning. Students who don't gain this addition fact fluency by the end of 2nd grade tend to struggle with the multiplicative reasoning in third. Having this fluency also allows them to work on more complex tasks because the have the fact recall to focus on the higher level concepts.

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