IM 7.4.13 Lesson: Measurement Error

Your teacher will give you 2 rulers & 3 line segments labeled A, B, & C. Use the cm ruler to measure each line segment to the nearest cm. Use the mm ruler to measure each line segment to the nearest tenth of a cm. Record measurements in the table.

A soccer field is 120 yards long. Han measures the length of the field using a 30-foot-long tape measure and gets a measurement of 358 feet, 10 inches.

What is the amount of the error?

Express the error as a percentage of the actual length of the field.

Your teacher will tell you which three items to measure. Keep using the paper rulers from the earlier activity.[br][list=1][*]Between you and your partner, decide who will use which ruler.[/*][*]Measure the three items assigned by your teacher and record your measurements in the first column of the appropriate table.[/*][*]After you finish measuring the items, share your data with your partner. Next, ask your teacher for the actual lengths.[/*][*]Calculate the difference between your measurements and the actual lengths in both tables.[/*][*]For each difference, what percentage of the actual length is this amount? Record your answers in the last column of the tables.[/*][/list]

Using the cm ruler:

Using the mm ruler:

Before there were standard units of measurement, people often measured things using their hands or feet.

Measure the length of your foot to the nearest centimeter with your shoe on.

How many foot-lengths long is your classroom? Try to determine this as precisely as possible by carefully placing your heel next to your toe as you pace off the room.

How many foot-lengths long is your classroom? Use this information to estimate the length of your classroom in centimeters.

Use a tape measure to measure the length of your classroom. What is the difference between the two measurements? Which one do you think is more accurate?