How do you convert a decimal to a percent?
EX a. 1.22
EX b. .384
Multiply by 100. Or simply move decimal point 2 places to the RIGHT. Don’t forget to add a percent sign.
EX a. 122%
EX b. 38.4%
How do you convert a percent to a decimal?
EX a. 73.7%
EX b. 138%
Divide by 100. Or simply move the decimal 2 places to the LEFT. Drop the percent sign.
EX a. 0.737
EX b. 1.38
How do you convert a decimal to a fraction?
EX a. 1.07
EX b. 0.516
For numbers greater than 1, move the decimal point until you have a whole number. This becomes the numerator. The denominator begins with 1 and put the same number of zeros as you moved the decimal to make the whole number.
EX a. 1.07 = 107/100
For numbers less than 1, 0.516, for example, use 516 as your numerator and the place value of the last decimal digit as the denominator (in this case, thousandths).
EX b. 0.516 = 516/1000
How do you convert a fraction to a decimal?
EX a. 19/10
EX b. 13/50
Divide the numerator by the denominator
EX a. 19/10 = 1.9
EX b. 0.26
- How do you convert from a percent to a fraction?
EX a. 75% - How do you convert from a fraction to a percent?
EX b. 3/4
- First convert the percent to a decimal. Then convert the decimal to a fraction
EX a. 75% = .75 = 75/100 = 3/4 - First convert the fraction to a decimal. Then convert the decimal to a percent.
EX b. 3/4 = .75 = 75%
What is PEMDAS?
the order of operations and how you should proceed to solve math equations:
Parentheses, exponents, multiplication, division, addition, subtraction. multiplication, and division, addition and subtraction happen from left to right.
- when given a fraction bar such as this, 36-6/12+3, solve the equation on top and on bottom before dividing.
When ordering numbers from smallest to largest, how do you make sense of fractions, decimals, ect.?
EX a. -5, 5 2/3, .523
EX b. which is greater, 8.33 or 8 2/3?
Try to get all the numbers in the same format, such as decimals.
EX a. -5, 0.523, and 5.666
EX b. 8.33 < 8.666
If comparing fractions, find the least common denominator to compare.
Story Problems: sum: difference: product: quotient: how many mL for a cc?
sum = addition difference = subtraction product = multiplication quotient = division 1mL= 1cc
Rounding rules:
1. What digit do you look at when rounding?
- If this digit is 5 or greater what do you do? If less than 5?
- How do you round a fraction?
- Only consider the digit immediately to the right of the place which you are rounding.
- Round up. Drop the digits that follow.
- convert fraction to a decimal and round to the desired place.
kilo: deca: deci: centi: milli:
kilo: 1000
centa: 100
deca: 10
deci: 1/10
centi: 1/100
milli: 1/1000
systems of measurement in metric:
- weight/mass:
- Volume:
- Linear distance:
metric systems of measurement:
weight: grams
volume: liter
distance: meter
systems of measurement in US:
- weight/mass:
- Volume:
- Linear distance:
US systems of measurement:
- weight/mass: ounce, pound, tonne
- Volume: fl ounce, pint, quart, gallon
- Linear distance: inch, foot, yard, mile
- what is the unit conversion between 1lb and 1kg?
2. what is the unit conversion between ounces and grams?
1Kg=2.2lb or .45kg=1lb.
1 ounce= 28.35g
- how many pints in a quart?
- how many quarts in a gallon?
- how many quarts in a liter?
- how many cc’s are in a ml?
2 pints = 1 quart
4 quarts = 1 gallon
1 quart = .95 liter
1cc = 1ml
- how many feet in one yard?
- how many feet in a meter?
- how many yards in a mile?
- how many kilometers in a mile?
- how many cm are in 1 inch
3 feet = 1 yard 3.048 feet = meter 1760 yards = 1 mile 1.6 kilometers = 1 mile 2.54cm = 1 inch
Area formulas:
- squares and rectangles:
- Parallelograms:
- Triangles:
- Trapezoids:
- Rhombus (diamond shape)
- Circles:
- length x width
- b x h
- 1/2 b x h
- 1/2 x h (b1+b2)
- 1/2 x d1 x d2
- pi x r^2
How to find the circumference of a circle?
How to find the length of an arc (part of a circle)
2 x pi x r
(n/360) 2 x pi x r {n is the central angle measure divided by 360, which is the degree of the whole circle}
How do you add or subtract fractions?
- find the LCD and rewrite fractions with the same denominators.
- Remember to multiply the numerators by whatever you multiplied the denominators by.
- Then you can add or subtract the numerators and add or subtract the denominators.
How do you add or subtract mixed numbers?
- add or subtract the whole numbers first to get the sum/difference of the whole numbers.
- Then find the LCD and proceed with adding or subtracting the denominators.
How do you multiply or divide fractions?
- Multiplication: see if you can cross cancel anything first, then proceed by multiplying the numerators and then the denominators.
- Division: multiply by the reciprocal of the second fraction.
How to multiply/divide mixed numbers?
- Multiply the denominator by the whole number and add the numerator (retain the same denominator). This will give you an improper fraction. Do this with all the mixed numbers in the equation.
- Then you can multiply numerators and denominators. If fraction is improper at the end, divide numerator by denominator and rewrite as a mixed number. * whole number is the number of times the denominator goes into numerator. Remainder is numerator, and denominator is retained.
- Follow same procedure with division: first make improper fractions then multiply by the reciprocal of the second fraction.
