Math module 2 lesson 2
- 1. Place Value and Problem Solving with Units of Measure Module 2: Lesson 2 Objective: Relate skip-counting by 5 on the clock and telling time to a continuous measurement model, the number line.
- 2. Fluency Practice Group Counting (3 minutes) Count forward and backward using the following suggested sequence, occasionally changing the direction of the count: Sevens to 35, emphasizing the transition of 28 to 35 Eights to 40, emphasizing the transition of 32 to 40
- 3. Fluency Practice Tell Time on the Clock (3 minutes)
- 4. Fluency Practice Minute Counting (6 minutes) Direct students to count by 5 minutes to 1 hour, to the half hour, and quarter hours. Repeat the process using the following suggested sequence for count-by: 6 minutes, counting to the hour and half hour 3 minutes, counting to a quarter past the hour and half hour 10 minutes, counting up to 1 hour 9 minutes, counting to 45 and emphasizing the transition of 36 to 45
- 5. Application Problem. (5 minutes) Christine has 12 math problems for homework. It takes her 5 minutes to complete each problem. How many minutes does it take Christine to finish all 12 problems?
- 6. Concept Development (33 minutes) Part 1: Explore seconds as a unit of time. It takes Ms. Bower 5 seconds to tie one shoe. Does it take a very long time to tie a shoe? Let’s see how long a second is. (Let the stopwatch tick off a second.)It’s a short amount of time! Let’s see how long 5 seconds is so we know how long it takes Ms. Bower to tie 1 shoe. (Let the stopwatch go for 5 seconds.) Let’s see how long 40 seconds lasts. That’s the amount of time it takes Ms. Bower to tie 8 shoes. (Let the stopwatch go for 40 seconds.) Tell the count at each 5 seconds.
- 7. Concept Development (33 minutes) Part 1: Draw a number line and relate skip-counting by fives to skip- counting intervals of 5 minutes. A different way to model this problem is to use a number line. Let’s use our tape diagram to help us draw a number line that represents a total of 60 minutes. Draw a line a few centimeters below the tape diagram. Make it the same length as the tape diagram. Make tick marks on the number line where units are divided on the tape diagram.
- 8. Concept Development What do you notice about the relationship between the tape diagram and the number line? What part of the tape diagram do the spaces between tick marks represent? We know from yesterday that time doesn’t stop. It was happening before Tori started her homework, and it keeps going after she’s finished. To show that time is continuous, we’ll extend our number line on both sides and add arrows to it.
- 9. Concept Development (33 minutes) Let’s label our number lines. The space between 2 tick marks represents a 5 minute interval. Write 0 under the first tick mark on the left. Then skip-count by fives. As you count, write each number under the next tick mark. Stop when you’ve labeled 60. 0 5 10 15 20 25 30 35 40 45 50 55 60 The space between 2 marks represents one 5 minute interval. How many minutes are in the interval from 0 to 10? From 0 to 60? From 15 to 30? Let’s use the number line to find how many minutes it takes Christine to do 4 math problems. (Place finger at 0. Move to 5, 10, 15, and 20 as you count 1 problem, 2 problems, 3 problems, 4 problems.) It takes Christine 20 minutes to do 4 math problems. Use the word interval to explain to your partner how I used the number line to figure that out.
- 10. Concept Development (33 minutes) Part 2: Use a number line to tell time to the nearest 5 minutes within 1 hour. Use your ruler to draw a 12-centimeter number line. How many 5 minute intervals will the number line need to represent a total of 60 minutes? Marking 12 equally spaced intervals is difficult! How can the ruler help do that? Use the centimeters on your ruler to draw tick marks for the number line. (Model.) Just like on the first number line, we’ll need to show that time is continuous. Extend each side of your number line and make arrows. Then skip-count to label each 5 minute interval starting with 0 and ending with 60. (Model while students follow along.) How many minutes are labeled on our number line?
- 11. There are 60 minutes between 1:00 p.m. and 2:00 p.m. Let’s use the number line to model exactly when we will do the activities on our schedule that happen between 1:00 p.m. and 2:00 p.m. Below the 0 tick mark, write 1:00 p.m. Below the 60 tick mark, write 2:00 p.m. (Model.) Concept Development (33 minutes)
- 12. Now this number line shows the hour between 1:00 p.m. and 2:00 p.m. We start recess at 1:10 p.m. Is that time between 1:00 p.m. and 2:00 p.m.? Find that spot on the number line, I’ll put my finger on 1:00 and move it to the right as I skip-count intervals until I reach 1:10. Remind me, what are we counting by? I’ll draw a dot on the spot where the tick mark and number line make a t and label it R for recess. (Draw and label as shown to above.) That dot shows the location of a point. Finding and drawing a point is called plotting a position on the number line. At 1:35 p.m., we’ll start science. Is 1:35 p.m. between 1:00 p.m. and 2:00 p.m.? T: Plot 1:35 p.m. as a point on your number line. Label it C. How does the number line you’ve labeled compare to the analog clock on the wall?
- 13. Concept Development (33 minutes) Part 3: Relate the number line to the clock and tell time to the nearest 5 minutes. We counted by fives to plot minutes on a number line, and we’ll do the same on a clock. How many 5-minute intervals show 15 minutes on a clock? We started at 0 on the number line, but a clock has no 0. Where is the starting point on a clock? Let’s count each 5-minute interval and plot a point on the clock to show 15 minutes. (Model.)
- 14. Concept Development 33 minutes Options for further practice: Plot 30 minutes, 45 minutes, and 55 minutes using the process above. Write 9:15 a.m., 3:30 p.m., and 7:50 a.m. on the board as they would appear on a digital clock, or say the time rather than write it. Students copy each time, plot points, and draw hands to show that time. (Model drawing hands with 10:20 a.m.)
- 15. Problem Set (10 minutes) You have 10 minutes to complete the problem set pages. Debrief (10 minutes) Let’s review your solutions for the problem set. How did our minute counting and time telling activities in today’s fluency help you with the rest of the lesson?
- 16. Exit Ticket (3 minutes) This is where you are going to show us that you understand what we learned today! We will learn if you are ready for the next lesson!
- 17. Homework 3-2 Homework Worksheet Is Due Tomorrow!