This document discusses units of measurement in the metric system including kilometers, meters, hectares, centimeters and millimeters. It explains how to convert between units by multiplying or dividing by powers of ten. The document also covers calculating the perimeter and area of different shapes such as squares, rectangles, triangles, trapezoids and composite shapes made of multiple simple shapes. Perimeter is defined as the distance around an object while area is the space inside the object. Formulas are provided for calculating the area of different shapes.

1. Math journal
Chapter 9

2. Metric system
• The standard measurements for the metric
system is: km, m, ha, cm, mm, hm
• You convert measurements by dividing or
multiplying powers of ten.
Examples
1km / 1000= 1 meter 1000meters *1= 1km
1m / 100 =1cm 100cm*1=1m
1cm / 10=1mm 10mm*1=1cm

3. perimeter
• Perimeter is the distance around a object
• To find the perimeter you add up all the sides
Examples
1: The distance around a field 2: Fencing around
your house 3: Picture frames

4. Area
• Area is the space inside the object
• To change between units for area you multiply
or divide by powers of ten
Examples
1: Area of wall to put wallpaper/paint 2: Area of
room to put furnishings 3: Area of door to put
pictures on
1kˇ2/1000000=1mˇ2 1000000mˇ2*1=1kˇ2
1mˇ2/10000=1cmˇ2 10000cmˇ2*1=1mˇ2
1cmˇ2/100=1mmˇ2 100mmˇ2*1=1cmˇ2

5. Area of shapes
• To find the area for a square, rectangle, and
parallelogram, you do base times height
• To find the area of a triangle you do base
times height divided by 2
• To find the area of a trapezoid you add both
bases( top and bottom), then you divide the
height by 2. Then you multiply it.

6. Examples for Area of Shapes

7. Composite shapes
• Composite shapes are shapes with two or
more simple shapes
• To find the area of a composite shape you
have to separate the two or more shapes then
find the area of them. Then you add both
answers together.

8. Composite Shapes Examples

9. THE END