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### Course: 3rd grade (2018 edition)>Unit 5

Lesson 1: Area introduction

# Intro to area and unit squares

Together, we'll explore a video introducing area by comparing two figures' space on a surface. Using unit squares, we'll measure their areas, emphasizing the importance of a unit square for measuring various shapes. Created by Sal Khan.

## Want to join the conversation?

• how does area help the real world
• Area is used for many things. Here are a few...
1) How large is the plot of land that I own?
2) How large is my house or apartment?
3) I want to paint a room. How much paint I need to buy is based upon the area of the walls of my room..
4) I wand to carpet a floor. Carpeting and other types of flooring are sold by the square foot, which is a measurement of area. So, I need to calculate the area of my room to find out how much carpet to buy.
• how he finds the amount is by using unit square
• Using units squared will give you the answer as long as the shape you are measuring can be divided by the area of units squared. So doing this in a mathematical sense without using physical shapes, you would divide the Unit squared by the objects area. Ex. How many times would a 1cm unit go into a 3cm unit, 3 times. Because we multiplied the 1cm unit x3 to get our answer.
• What is it called when it is 4-D(example:3-D,cube units/2-D,square units)?
• There's no name for it yet...
Scientists suggest that 4 Dimensional could be time.
• what if you dont have UNIT SQUARES?
• Unit rectangles
• how do you find the prminiter
• To find the perimeter, find the total number of units (distance) around the edges of the shape.

Have a blessed, wonderful day!
• Is the unit square have to have the lengths so it could be a unit square or can it be a unit square with different lengths Also can we use shapes that are different for example: a rectangle?

Thank you <3
• A square can have any side length as long as all the sides have the same length. For a square to be a unit square, its sides must be 1 unit long. If a square has side lengths that are not equal to 1, it cannot be called a unit square. Sure! You can use other shapes as long if they will make your work easier. For example, in the above video, if we used a 2 by 1 rectangle to measure, we would be able to put 2.5 rectangles in the blue figure and 5 rectangles in the purple figure.
• What if the square unit is cut in half? Would it be some number .5
• Yes, you would have to think of it as 1/2 unit square.
• doez me karector lok hansom?,?,\$*÷'(,#'(*?,×'*&×'>&×'×'
• me loky hansom
• So are we going to write it down
`A = (b * h) / 2`
`A = (2 * 10) / 2 = 20 / 2 = 10`