Presentation on theme: "Module 2 Lesson 9 Measure and compare lengths Review Mei’s frog leaped several centimeters. Then it leaped 34 centimeters. In all, it leaded 50 centimeter."— Presentation transcript:
Review Mei’s frog leaped several centimeters. Then it leaped 34 centimeters. In all, it leaded 50 centimeter. How far did Mei’s frog leap at first? Draw a picture and write a number sentence to explain. Read-read and if necessary re-read Understand- Underline what you know- Circle what you need to find out Solve – plan how it will be solved Check- does it make sense? ____ cm. + ____ cm. = 50cm.
Activity on the floor with teacher Will need meters and yarn
Can we estimate the length of the squiggly line and the zigzag line? Why can’t we estimate the lengths? Which line do you think is longer? line A line B
How can you find the actual length? Stretch them out and measure each part using string. line A line B
How can you find the actual length? Draw a diagram line A line B 3 meters 5 meters Are my lines really 3 and 5 meters long on the board? No. This is called a tape diagram. This is helpful because I can draw a small picture to show any length.
Draw the diagram line A line B 3 meters 5 meters Is my diagram correct? No, the 5 meter line needs to be a little longer. Lets draw the 5 meter line a little long.
You got it! line A line B 3 meters 5 meters What number sentence could we write to show the total length of the strings? 3 + 5 = _____
Draw the diagram line A line B 3 meters 5 meters What number sentence could we write to show the difference in length between the two string? 5 – 3 = _____
Practicing Tape Diagrams Let’s say the string around my wrist is 16 cm. and then string around my head is 38 cm. Can I draw the my actual head and wrist on my paper?
Tape Diagrams Let’s draw a diagram that represents my wrist and head. Wrist Head 16 cm. 38 cm. Do my diagrams make sense?
Tape Diagrams Let’s draw a diagram that represents my wrist and head. wrist head 16 cm. 38 cm. What is this open space between the end of the first and second bar?
Tape Diagrams The difference is how much longer the 38 cm. is than the 16 cm. wrist head 16 cm. 38 cm. Difference
Tape Diagrams Write a number sentence to show what the difference is between my head and wrist. wrist head 16 cm. 38 cm. Difference 38 cm. – 16 cm. = _____