Khan Academy Wiki

The Measuring area with unit squares exercise is under the 3rd grade (U.S.) Math Mission, Pre-algebra Math Mission and Mathematics I Math Mission. This exercise explores the concept of area specifically using square units and unit squares.

Types of Problems[]

There are two types of problems in this exercise:

  1. Find area of striped region: This problem has a grid drawn and the user is expected to find the area of the striped region by counting how many unit squares are striped.
    Area1

    Find area of striped region

  2. Find area of the shape: Although this problem is also shaded/colored this shape is drawn on a grid and seems to encourage the user to find the correct area by subdividing a shape into easier shapes rather than just counting.
    Area2

    Find area of the shape

Strategies[]

This exercise is medium to get accuracy badges because the interface makes it east to miscount the dimensions of the shapes. Speed badges are hard because of the time needed to be careful and get the right counts.

  1. In the first problem type, you can count the number of shaded squares in each row easier than dimensions, so you can use this ability to count the total slightly faster.

Real-life Applications[]

  1. Measurements are used for many things, such as cooking, and for placing carpet.
  2. The ancient Egyptians from over 4000 years ago were very good at shapes and geometry. Every time the Nile burst its banks and flooded the planes, they had to use geometry to measure their gardens and fields all over again.