7th Grade Science Student ebook

UNIT 1 LIVING SYSTEMS

Figure 1.2: Comparing the size of

living things and compounds.

length - a measurement of

distance.

area - a measurement of how

much surface something has.

Length and area

Measuring length Length is a measurement of distance. Life scientists measure the

length of a living thing along its greatest dimension. Figure 1.

shows a scale that compares the lengths of different living things

and the appropriate SI unit to measure each.

What is the length of the fish below? If you measured it to be

10.5 cm, you are correct!

Measuring area Area is a measurement of how much surface something has. A

coyote occupies a certain area of land called its territory. A coyote’s

territory is about 16 square kilometers (km^2 ). While this area

probably has an irregular shape, if a coyote’s territory was a

perfect square, you could measure the area as shown below.