Math Study Help (Grade 9 LD)
Changing a Fraction to a decimal
Example: 1/5 = 0.2
Example: 5/8 = 0.625
Percentages left to pay
We always start with 100%
A Keyboard is 25% off how much do we have
left to pay?
100% - 25% = 75% left to pay.
How much is tax on an item?
$34 baseball bat, how much is the tax?
Always remember tax is 13%
34 * 0.13 (Change 13% to a decimal) = 4.42
Add the two together to get total price. 34 + 4.42 = 38.42
Kg, G, Mg
1 Kilogram = 1000 Grams
1 Gram = 1000 Mg
Milo grams to Grams = amount * 1000
Main topic
M, Km, Cm, Mm, Inches, Feet
1 Kilometre = 1000 metres
1 Metre = 100 cetimetres
1 centimeter = 10 milimetres
12 Inches = 1 foot
1 metre = 3.28 feet
Changing a decimal to a percent
Example: 0.625 (multiply by 100) * 100 = 62.5%
Example: 0.9 * 100 = 90%
Example: 0.07 * 100 = 7%
How much do we pay for sale price items?
A Hockey stick is 149.99 and is 15 percent off.
What is the 15%? 149.99 * 0.15 (change percent to
a decimal) =$22.50
Find the sale price: 149.99 - 22.50 = 127.49
Rounding (Hundreds and Tens)
Rounding to the nearest hundred:
384=400 , 249=200 , 123=100
Rounding to the nearest ten:
56=60 , 42=40 , 97=100