Fraction and Decimal Math
Fraction math • Parts of a fraction Whole numberthe larger number at the front Numerator- The top number Denominator- The bottom number How much pizza in total?
Fraction math •
Adding and subtracting fractions
1.
Like denominators --Just add or subtract the numerators. Place the answer over the common denominator Unlike denominators -You must 1st use multiplication to make one denominator look like the other one. You then follow the step one strategy
2.
3 x2 6 now put back in 8 x2 = 16 and subtract
Fraction math • An improper fraction is a fraction where the numerator (the top number) is greater than or equal to the denominator (the bottom number). In other words, it is top-heavy. This needs to be made into a mixed numeral
Example: 5/3 (five thirds) and 9/8 (nine eighths) are improper fractions
Converting Improper Fractions to Mixed numeral • To convert an improper fraction to a mixed fraction, follow these steps: •* Divide the numerator by the denominator. • * Write down the whole number answer • * Write down any remainder above the denominator.
Fraction math •1ST WAY •Example: Convert 7/4 to a mixed fraction. •Divide: 7 ÷ 4 = 1with a remainder of 3 •Write down the 1 as a whole numberthen write down the remainder (3) as the numerator above the denominator (4), • answer
1
2ND WAY
3 4
• Converting Mixed numerals to Improper Fractions • To convert a mixed fraction to an improper fraction, follow these steps:
•*
Multiply the whole number part by the fraction's denominator. • * Add that to the numerator • * Then write the result on top of the denominator.
Fraction math •Example: Convert 3 2 to an 5 improper fraction. •Multiply the whole number by the denominator: 3 × 5 = 15 •Add the numerator to that: 15 + 2 = 17 •Write that down above the denominator, like this: 17
5
Adding or subtracting • Adding mixed numerals Check to see if the denominators are the mixed numerals same, if not find a common denominator Add whole numbers to whole numbers and fractions to fractions Reduce the fraction Place together for the answer
• Subtracting mixed numerals Check to see if the denominators are the same, if not find a common denominator A) Subtract whole numbers to whole numbers and fractions to fractions B) You may need to convert to improper fractions if your 2nd fraction is lower then the first, then subtract Reduce the fraction Place together for the answer
Converting to an improper fraction
Adding and Subtracting decimals • • • •
Rules - always align your decimal places - Take into account significant digits -Add or subtract with regular rules ( in other words borrow and carry)
Eg. 5.6 + 8.01
5.60 +8.01 13.61
Multiplication and Division of decimals • Multiplication (roving decimal-moving) multiply as if the decimal is not there. When you get your answer, you count the decimal places in the two numbers being multiplied and move that many spaces in your answer
Division (the Floater) -The decimal floats up to the top before you even divide.
• Multiplication • 2.31 = 231 x 6.1 x 61 • 231 • 13860 » 14091 =once we move the decimal 14.091
Division with decimals 0.321 10) 3.21
10) 3 21 -0 32 -30 21 -20 10 -10 0
Ans.= 0. 321
Calculating Percent of an object
• You simply • 1) Convert % to a decimal • 2) multiply by the amount of money
30 % of $6.99
6.99 X .30 total of 4 decimal spaces 000 20970 20970 move the decimal 4 spaces -round if necessary to the nearest penny ANS.= $2.097 Rounded to the nearest penny =$ 2.10
Calculating % off • You use the total price and multiply by it’s percentage ( as a decimal) $30.21 with 10% off 30.21 X 0.1 3021- move the decimal 3 places Ans.= $3.02
We can then calculate the new price by taking this answer and subtracting it from the 1st amount $30.21 -______
Percentage and pie graphs Imagine Norman asked 800 people what their their favourate movie. How many liked each type?
• We can use ratios and equivalent ratios to solve pie graphs with totals over 100