C3 Fractions and Decimals Flashcards
Reciprocal
two numbers whose product is 1, also called the multiplicative inverse
4/3 is the reciprocal of 3/4 when multiplied together the product is 1.
increasing the terms of a fraction: what are the steps?
multiply both the numerator and the denominator by the same number
example:
3/4 x 2 = 6/8
cross multiplication for comparing fractions: what are the steps?
- Multiply the numerator of the first fraction by the denominator of the second fraction and jot down the answer.
- Multiply the numerator of the second fraction by the denominator of the first fraction and jot down the answers.
STEPS: 1X2 3X4
- Compare the two numbers, the larger number is the larger fraction
Note: only work with two fractions at a time, determine the which one is the greatest and then toss the smallest one and compare the greatest with the next one.
multiplying fractions: what are the steps?
- Change the mixed numbers into improper fractions
- Multiply the numerators together and the denominators together
- Reduce all the way
Tip: you can also make multiplying easier by first canceling out equal factors in the numerators an the denominators (on the diagnal) of each fraction.
dividing fractions: what are the steps
multiply the first fraction by the reciprical of the second fraction.
- Change the mixed numbers into improper fractions
- Flip the second fraction, placing the denominator on top and the numerator on the bottom. (THE RECIPRICAL)
- Change the division sign to multiplication
- Continue as with multiplication of fractions
adding fractions with same denominator: what are the steps?
add the numerators and leave the denominator unchanged
adding fractions with different denominators the easy way; what are the 3 steps?
- multiply the numerator of each fraction by the denominator(s) of the other fraction(s), add the results of each multiplication, place the sum as the new numerator.
- multiply all the denominators together, the product of the denominators is your new denominator
- reduce as neccessary
adding fractions with different denominator the traditional way; what are the 3 steps?
- find the least common multiple (LCM) of the two denominators
- Increase the terms of each fractions so that the denominator of each equals the LCM.
- Add the new fractions (add the numerators and leave the denominator unchanged)
subtracting fractions with the same denominator; what are the steps?
subtract the numerator of the second fraction from the numerator of the first fraction and leave the denominator unchanged
subtracting fractions with different denominators the easy way; what are the 3 steps?
- cross multiply the two fractions (numerator of first by denominator of 2nd and vice versa) and subtract the second number from the first for you new numerator.
- multiply all the denominators together to get the new denominator
- put the new numerator over the denominator to get your answer
subtracting fractions with different denominators the traditional way; what are the 3 steps?
- find the least common multiple (LCM) of the two denominators
- Increase the terms of each fractions so that the denominator of each equals the LCM.
- Subtract the new fractions (subtract the numerators and leave the denominator unchanged)
convert mixed number to improper fraction: what are the steps?
- multiply the denominator of the fractional part by the whole number, and add the result to the numerator.
- use this result as your new numerator, and place it over the existing denominator
converting improper fraction to a mixed number: what are the steps?
- divide the numerator (dividend) by the denominator (divisor)
- the quotent (answer) becomes the whole number part
- the remainder (answer) becomes the new numerator
- the denominator of the improper fractions is still the denominator
ratio
is a mathematical comparison of two numbers, based on division
2:3 is the same as 2 to 3 and 2/3
adding decimals: what are the steps
- arrange the numbers in a column and line up the decimal points
- add as usaul, column by column, from right to left
- Place the decimal point in the answer in line with the other decimal points vertically