SWBAT express that measuring an object using different length units will result in different measurements. SWBAT solve problems about comparing lengths.

Move over Van Halen because today we are all going to "Jump." So go ahead and jump as students solve an assessment piece and story problems involving jump lengths. If you are under 30, please Google Van Halen before proceeding.

3 minutes

I start the lesson with a time activity that has students reading an analog clock and telling time to the hour. This is a continuation from the skills introduced in the previous lesson. I want to continue to reinforce this concept and allow students to demonstrate their abilities as I informally assess.

*"I would like to continue to work with the analog clock that we used yesterday. Let's do a quick review. WHich hand is the hour hand (red one) and which are the hour numbers (red ones on clock face)? Which hand is the minute hand (blue one)? Which numbers are the minute numbers (blue ones). Why is the minute hand so long (it has to reach the minute numbers on the edge of the clock)? Who could come up and se this clock so that it says 2:00? WHo can set it for 5:00? WHo can tell me what time this is (set the clock for 8:00)?"*

I repeat this for several more hour times. The Core Standards expect that 1st graders can tell and write time in hours and half-hours using analog and digital clocks (CCSS.Math.Content.1.MD.B.3).

The students are using clocks to read times and placing hour and minute hands to represent set times. The core expects that "mathematically proficient students to consider the available tools when solving a mathematical problem and that they are sufficiently familiar with tools appropriate for their grade or course to make sound decisions about when each of these tools might be helpful (CCSS.Math.Practice.MP5)"

15 minutes

**"Today during stations, you are going to be working on two different activities. One activity is an assessment task, that will allow me to see how you are doing with your measurement knowledge. You must work on this by yourself, so that I can get an idea about how you are thinking about measurement."**

This problem will let you see if students understand that when measuring the same object, different sized units yield different counts.

*"The second activity is a packet of story problems that involve measurements. I will be happy to read the problems to you if you need help. Remember to show how you solved the problem and to write an equation to represent your thinking."*

* "You can start with either activity but you must get to both of them today."* If a student starts with the story problems, just make sure that they have enough time to solve the assessment task. You want each student to complete that task before the end of the lesson.

The assessment task and the story problems are in the section resource. Make sure to make enough copies for each student in your class.

The Common Core expects students to make sense of problems and persevere in solving them. That mathematically proficient students start by explaining to themselves the meaning of a problem and looking for entry points to its solution. Younger students might rely on using concrete objects or pictures to help conceptualize and solve a problem (CCSS.Math.Practice.MP1).

30 minutes

The students now work on the two activities that were introduced in the previous section. You should circulate around to each student as they are working on each activity. Again, as students work on the assessment task, you want to notice if the students understand that when measuring the same object, different sized units yield different counts. There is an example of a completed task int he section resource. This is an example of a student who has met the standard on the assessment task.

As students work not he story problems, you should observe if:

- students are able to read the problem and visualize the situation.
- students are able to identify these problems as combining two amounts or comparing two lengths to see which is more.
- What strategies do the students use to combine these two quantities? Are the students combining both groups and count all? Do they count on from one number? Do they use a known fact.
- What strategies do students use to compare two lengths? Do students model the problem with counters and directly compare? Do they count on or back from one number? Do they use a number relationship? Do they use counters or a number line?

I have included a video of a student explaining how they solved the task. This will give you an idea of what you are looking for.

When students are working on story problems, they are Using addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem (CCSS.Math.Content.1.OA.A.1). The Core expects all first graders to be able to do this by the end of the school year.

15 minutes

I wanted to end the lesson with a discussion that would reinforce the concept that measuring the same object with different sized units will yield different counts. Watch the video to see how I accomplished this goal. The video is just over 6 minutes long but it clearly reiterates the focus and allows for a solid generalization by the students.

The students are developing their own rationale during this discussion and listening to others thoughts as well. It is expected that students can construct viable arguments and critique the reasoning of others**. **They are able to analyze situations by breaking them into cases, and can recognize and use counterexamples. They justify their conclusions, communicate them to others, and respond to the arguments of others. Elementary students can construct arguments using concrete referents such as objects, drawings, diagrams, and actions. Students at all grades can listen or read the arguments of others, decide whether they make sense, and ask useful questions to clarify or improve the arguments (CCSS.Math.Practice.MP3).

This discussion/activity also has students ordering three objects by length; compare the lengths of two objects indirectly by using a third object (CCSS.Math.Content.1.MD.A.1).

10 minutes

To continue to focus on fact fluency and the use of the +, -, and = signs. The sheet is int he section resource. The students should work on this individually.

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