Arithmetic

Question 1

Multiplying fractions

Answer 1

multiply numerators by each other and denominators by each other.

Question 2

Dividing fractions

Answer 2

Flip the numerator and the denominator of the fraction that your dividing by, then multiply.

Question 3

Adding Fractions

Answer 3

you can add fractions only when they have the same denominator. When you add, add only the numerator, NOT the denominators

Question 4

What is the common denominator

Answer 4

When you have to find a common number that the numbers in the fraction share in order to add and subtract.

Question 5

Subtraction fractions

Answer 5

only subtract the numerator with a common denominator.

Question 6

Reducing Fractions

Answer 6

Whenever there is a common factor in the numerator and denominator, you can reduce the fraction by removing the factor from both parts of the fraction.

Question 7

Canceling

Answer 7

when ever you have to multiply two or more fractions, you should cancel common factors before you multiply. Similar to reducing.
ex. (1/2)(2/1) = 1/1

Question 8

Comparing fractions

Answer 8

One way to compare fractions is to re-express them with a common denominator. Or convert them to decimals.

Question 9

What is a mixed number

Answer 9

consist of an integer and a fraction. For example 1(3/4)

Question 10

Improper fraction

Answer 10

when the numerator is greater than the denominator.

Question 11

To convert an improper fraction

Answer 11

to a mixed number, divide the numerator by the denominator. the number of whole times that the denominator goes into the numerator will be the integer portion of the improper fraction. the remainder will be the fraction

Question 12

Adding and subtracting mixed numbers

Answer 12

first add/ subtract the integer parts, next add/subtract the fractional parts. When subtracting and the mixed number is smaller than the fraction then convert it to an improper fraction. and continue.

Question 13

Setting up a ratio

Answer 13

to find a ratio put the number associated with the word of on the top and the quantity associated with the word to on the bottom and reduce.

ex. the ratio of 20 oranges to 12 apples is 20/12= 5/3

Question 14

Part to part ratios and part to whole ratios

Answer 14

if the parts add up to a whole, a part to part ratio can be turned into two part to whole ratios. by putting each number in the original ratio over the sum of the numbers.
ex ratio of males to females is 1 to 2 -> 1/3

Question 15

Solving a proportion

Answer 15

to solve a proportion, cross multiply

Question 16

Changing fractions to decimals

Answer 16

divide the denominator of the fraction into the numerator

Question 17

Changing decimals to fractions

Answer 17

to change decimals to fractions put the digits to the right of the decimal point in the numerator. to figure the denominator we put a 1 in the denominator and followed it with as many zeros as there were digits to the right of the decimal point.

Question 18

Addition and subtraction of decimals

Answer 18

you add and subtract decimals the same way you add and subtract whole numbers. just make sure the decimal points are lined up.

Question 19

Multiplication of decimals

Answer 19

multiply decimals as if they were whole numbers and worry about the decimal points later. To place the decimal point in the answer count the number of digits to the right of the decimal point of each number, then place the decimal in the answer of the sum.

Question 20

Division of decimals

Answer 20

express the division in fractional form. then make both the numerator and denominator a whole number by multiplying it by 10. then divide the denominator into the numerator.

Question 21

Rounding decimals to nearest place

Answer 21

to round a decimal to the nearest place, look at the digit immediately to the right of that place. if the digit 5 or greater round up. if its 4 or less round down.

Question 22

Percent

Answer 22

any percent can be expressed as a fraction with the denominator of 100. percent means per one hundred.

Question 23

convert a percent to a decimal

Answer 23

just drop the percent symbol and divide the number by 100.

Question 24

percent formula

Answer 24

percent=part/whole

percent x whole=part

Question 25

percent increase

Answer 25

%increase= amount of increase/original whole(%100)

ex if X is 10% greater than Y then X is 110% of Y

Question 26

percent decrease

Answer 26

%decrease= amount of decrease/original whole(%100)

ex if X is 70% less than Y, then X is 30% of Y

Question 27

New whole

Answer 27

new whole= original whole +- amount of change

Question 28

Averages

Answer 28

to find the average set of numbers , add them up and divide by the number of terms (the number of numbers)
average= sum of the numbers/number of terms

Question 29

Using the average to find the sum

Answer 29

sum= (average) x (number of terms)

Question 30

Finding the missing number when given the average

Answer 30

to find a missing number when you’re given the average, use the sum.
ex. If the average of four numbers is 7. then 4 x 7= 28. if the numbers given are 3,5,6 they =14, 28-14= 7. which makes 7 the fourth number.

Question 31

Probability

Answer 31

the probability of an event is the possible number of desired outcomes divided by the total number of possible outcomes. its numerical value is always less than or equal to one. the probability of two independent events both occurring is the product of the individual probabilities.