ESTIMATION Estimation

means an approximate calculation.

Without actual measurement , we estimate Lily’s height to be 120 cm.

…we estimate the board’s length to be 2 wah.

…we estimate the box’ height to be 20 cm.

…we estimate the toy gun’s length to be 10 cm.

Guess

Baby Yan- yan’s height:

a. 68 cmb. 58 cm

The praying mantis’ length:

a. 32mmb. 35mm

Guess

Teacher Toto’s height:

a. 164 cmb. 250cm

Guess

The elephant’s height:

a. 2 wahb. 1 wah

Estimate

BLEEEEEEE!!!!!YOU’RE WRONG

HURRAY!!!!!YOU’RE RIGHT!

Exercises

1. Circle the appropriate eye-estimation.

a b

a. Length of a pen 140 cm 14 cm

b. Height of a student 120 m 120 cm

c. Height of my parent 160 cm 160m

d. Length of a desk 300cm 30m

e. Height of the room 8 m 80 cm

f. Height of a rubber 30 cm 3 cm

g. Length of a comb 20 cm 10 cm

h. Length of a notebook 30 cm 5 cm

2. Estimate the length or height of the objects below. Indicate the errors.

Objects

Estimate Measure Error

Example a. desk 58 cm 60 cm 60 -58= 2 cm

b. pencil

c. chair

d. rubber/eraser

e. notebook

3. Estimate the perimeter of the given shapes in centimeter.Then, measure using the ruler. Indicate the error.

Shapes Estimate (cm) Using ruler (cm) Error (cm)

Example:13-8

=5 cm

a.

b.

c.

d.

e.

5cm 3 cm

Perimeter= 13 cm Perimeter= 13 cm5cm

3 cm 2 cm

3 cm

Exercise 4: Solving Word Problems on Length

a. There are 4 poles located in equal distance from each other. If the distance between the first pole and the last pole is 9 km, what is the distance between the poles in meters.

w w w w9 km

? _ m ? _ m ? _ m

Exercise 4: Solving Word Problems on Length

b. The length of a harvest field is 60 wah. Find the length of one and a half of it in meters.

60 wah

Figure BFigure A

? m

Exercise 4: Solving Word Problems on Length

c. A cable wire with the length of 4 km is cut into 6 equal pieces. What is the length of each piece in meters.

4 km

? m? m

? m

? m

? m? m