Module 2Lesson 9 Measure and compare lengths

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-readUnderstand- Underline what you know- Circle what you need to find outSolve – plan how it will be solvedCheck- does it make sense?

____ cm. + ____ cm. = 50cm.

Activity on the floor with teacher

Will need meters and yarn

Next slide will be reviewing the activity

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. = _____

16 cm. + 38 cm. = ____

Work it Out

Tape Diagrams

Is there another way?

wrist

head

16 cm.

38 cm.

Difference

16 cm. + ____ = 38 cm.

16 cm. + ___ cm. = 38 cm.

Work it Out

Problem Set

Problem Set

Problem Set

Problem Set

Exit Ticket

Exit Ticket