VidaaraPlay
Door 15 · Grade 1

cm Length

Measure everything: long, short, tall!

▶ Play Door 15

Long, Short and Tall

LONG and SHORT compare how much something stretches.
A train is LONG, a pencil stub is SHORT.
TALL is for height: a giraffe is TALL, a mouse is SHORT.
To compare, place objects side by side from the same starting point.

Worked example

Problem: Which is taller: a tree or a flower?

  1. A tree grows many metres high.
  2. A flower is small.
  3. The tree is taller.

Answer: tree

Measuring with Non-Standard Units

Before rulers, we can measure with hand spans, footsteps, pencils or blocks!
A table might be 8 hand spans long.
But hands are different sizes, so answers can differ. That is why we need standard units!

Worked example

Problem: A book is 3 pencils long. Each pencil equals 1 unit. How many units long is the book?

  1. Count the pencils: 3.
  2. So the book is 3 units long.

Answer: 3

Introduction to Centimetres

The CENTIMETRE (cm) is a standard unit of length.
Your ruler shows centimetres from 0 to 15 or 30.
To measure, place the object at 0 and read the number at its end.
Your finger is about 1 cm wide!

Worked example

Problem: An eraser starts at 0 on the ruler and ends at 4. How long is it in cm?

  1. Read the number at the end: 4.
  2. The eraser is 4 cm long.

Answer: 4