Math journal

Chapter 9

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

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

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

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.

Examples for Area of Shapes

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.

Composite Shapes Examples

THE END