If two fractions have the same [positive] denominator, then the smaller numerator implies the smaller fraction. Furthermore, the ratio of the numerators is the ratio of the fractions.
So, for example, if you have
3/17 and 5/17 then, since 3 < 5, it follows that 3/17 < 5/17
and the two fractions are in the ratio 3:5. That is, the first fraction is 3/5 of the second.
All of the above remains true if you replace 17 by any other positive number (including an irrational number).
Numerator, Denominator or Denominator, Numerator.
If the numerators are equal, then here's what the denominator will tell you: The number with the largest denominator will will be the smallest number. For example: Compare 1/3 and 1/4. 1/4 is smaller because it takes 4 of those to make up 1 whole, while it only takes 3 thirds to make a whole. If the numerator is another number, the principal is the same, as long as all fractions have the same numerator.
A proper fraction is a fraction where the numerator is less than the denominator. In this case, all proper fractions with a denominator of 3 would have a numerator less than 3. Therefore, the proper fractions with a denominator of 3 would be 1/3 and 2/3. These fractions represent parts of a whole divided into three equal parts.
Adding and subtracting fractions can ONLY be done if the denominators are the same; then the calculation is done by adding or subtracting the numerators. Multiplying (and dividing) fractions does not require the denominators to be the same. To divide by a fraction the divisor is inverted (the original numerator becomes the new denominator and the original denominator becomes the new numerator) and then the fractions are multiplied. Multiplying fractions is achieved by multiplying the numerators together AND multiplying the denominators together. A whole number is the same as a fraction with the whole number as the numerator and a denominator of 1, so when multiplying by a whole number the denominator is multiplied by 1 (leaving it the same) and the is multiplication is effectively just multiplying the numerator by the whole number.
Fractions can only be added or subtracted if the denominators are the same. If the denominators are different, then the fractions need to be made into equivalent fractions with the same denominator. The new denominator can be found simply by multiplying the denominators together, but this can lead to some large fractions with which to work. A better new denominator is the lowest common multiple of (all the) denominators. (Once the new denominator is found, the fractions' new numerators are found by multiplying their current numerator by the new denominator divided by their current denominator to make their equivalent fractions with the new denominator.) Once all the fractions are converted into equivalent fractions with the new denominator then the fractions can be added or subtracted, with the result being simplified (if possible).
Numerator, Denominator or Denominator, Numerator.
Only Fractions with a Common Denominator can be directly compared.
One way to compare two fractions is to convert both to a common denominator. Then the only difference is in the numerator. Comparison of the numerator is then sufficient to compare the fractions. A percentage is equivalent to converting the fractions to a denominator of 100.
Only in improper fractions where the numerator is a multiple of the denominator.
If the numerators are equal, then here's what the denominator will tell you: The number with the largest denominator will will be the smallest number. For example: Compare 1/3 and 1/4. 1/4 is smaller because it takes 4 of those to make up 1 whole, while it only takes 3 thirds to make a whole. If the numerator is another number, the principal is the same, as long as all fractions have the same numerator.
simplest form
It depends on how you need to compare them. If you want to know which one is larger, just look at the denominator - a smaller denominator means a larger number. If you need to add or subtract them, the only thing you can do is make the denominators equal.
No. Only when fractions have a numerator bigger that their denominator can they be simplified as a mixed number.
A proper fraction is a fraction where the numerator is less than the denominator. In this case, all proper fractions with a denominator of 3 would have a numerator less than 3. Therefore, the proper fractions with a denominator of 3 would be 1/3 and 2/3. These fractions represent parts of a whole divided into three equal parts.
Adding and subtracting fractions can ONLY be done if the denominators are the same; then the calculation is done by adding or subtracting the numerators. Multiplying (and dividing) fractions does not require the denominators to be the same. To divide by a fraction the divisor is inverted (the original numerator becomes the new denominator and the original denominator becomes the new numerator) and then the fractions are multiplied. Multiplying fractions is achieved by multiplying the numerators together AND multiplying the denominators together. A whole number is the same as a fraction with the whole number as the numerator and a denominator of 1, so when multiplying by a whole number the denominator is multiplied by 1 (leaving it the same) and the is multiplication is effectively just multiplying the numerator by the whole number.
GCF doesn't apply to fractions, only to whole numbers. When those numbers are the numerator and denominator of a fraction, the GCF can be used to reduce it to its simplest form.
You can compare two fractions by dividing numerator / denominator on your calculator. In this case, since the integer part is the same, you only have to divide 8/12, and 6/9.