Yes, then do the same for the denominators. But THEN you are usually expected to simplify the resulting fraction.
Usually for baking.
You look for a common denominator; convert the fractions to equivalent fractions with the denominator you found; then you do the addition itself.
Convert them to one or the other. Your answer will usually be more accurate if you're adding fractions.
Usually they are ordered from smallest to largest.
No because in order to subtract or add fractions the denominator of the fractions must be the same and if they are not then the lowest common denominator of the fractions must be found. Having subtracted or added the fractions then it may be possible to simplify the result.
I assume you mean, with different denominators. If you want to add the fractions, subtract them, or compare them (determine which one is greater), you have to convert them to similar fractions (fractions with the same denominator) first. Converting to similar fractions is not necessary, and usually doesn't even help, if you want to multiply or divide fractions.
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).
Petrol, fuel oil , disel oil
Usually smallest to largest, least to greatest.
There are many adding fractions worksheets to download online at fractions for you dot com. The best I have found to download and print instantly and then use at home.
There is none. A least common denominator is to be found between or among fractions. 3 and 7 are not fractions.