Question

example jerry’s outstretched hand is 20 cm. he uses his hand to estimate the length of this piece of paper. number of jerry’s hands: 1 1/2 estimated length of paper: 1.5 x 20cm = 30cm actual length: 28 cm practice complete the following chart: item to be measured, personal reference, estimate, measurement height of classroom, length of classroom, thickness of a loonie, capacity of a pop can unit 3 - measurement mat2l - 4 -

Explanation:

Step1: Choose personal references

For height of classroom, can use average - height person (about 170 cm). For length of classroom, can use long - step (about 80 cm). For thickness of a loonie, can use thickness of a fingernail (about 1 mm). For capacity of a pop can, can use a small water bottle (about 500 ml).

Step2: Calculate estimates

Height of classroom: Assume 2 average - height people stacked, so estimate is $2\times170 = 340$ cm.
Length of classroom: Assume 20 long - steps, so estimate is $20\times80=1600$ cm.
Thickness of a loonie: Assume 2 fingernail - thicknesses, so estimate is $2\times1 = 2$ mm.
Capacity of a pop can: Similar to small water bottle, so estimate is 500 ml.

Answer:

Item to be measured	Personal Reference	Estimate	Measurement
Length of classroom	Long - step (80 cm)	1600 cm	Varies (usually 600 - 1000 cm)
Thickness of a loonie	Thickness of a fingernail (1 mm)	2 mm	About 1.95 mm
Capacity of a pop can	Small water bottle (500 ml)	500 ml	About 355 ml