Rullst AcademyRullst Academy/Lesson
Mathematics: a garden of numbers · Lesson 05 / 06

Measure and go around

A garden drawing needs measurements. Lia will measure a ribbon and calculate the outline of a small rectangle.

Learning paths6 min

Let's discover together

  1. 1

    A measurement needs a unit: 8 centimeters and 8 meters are not the same length. Here we use centimeters, abbreviated cm.

  2. 2

    On a ruler, length is the difference between the end and start marks. A ribbon from 5 cm to 13 cm measures 13 − 5, not 13 cm.

  3. 3

    Perimeter is the length of the entire outline. A rectangle with sides 4 cm and 2 cm has four sides: 4, 2, 4 and 2. Add them all.

✦
YOUR MISSION

Calculate a length from the difference between marks and the perimeter of a rectangle.

Now it's your turn

Discovery workshop

Measure and go around

Ribbon: starts at the 5 cm mark and ends at the 13 cm mark. Drawing’s rectangle: sides of 4 cm, 2 cm, 4 cm and 2 cm.
Build your answers and check when you are ready.
A moment to understand

Perimeter measures…

I need a hint

Imagine an ant walking once around the edge.

Loading your journey…

Take it with you

Draw a rectangle, label all four sides with the same unit and check the sum by following the edge.

At your own pace

My files and GitHub

Every lesson can become your own record: code, notes or a practice plan. Saving a file to GitHub is optional and does not change your XP.

Student guide

The editor and downloads open when this lesson is available to your account. Check access below or return to the track map.

Checking your access to this lesson…

Rullstpetbot

AI can make mistakes. Check the lesson material.