How do i write fractions in lowest terms?

Question

Something Like 28
140

Answer 1

It is a bit of guesswork, but look at prime numbers that each can be divided by evenly. For instance, bith numbers are even, so divide by 2, giving you 14/70. doing it again gives you 7/35. Both are divisible by seven, so try again---1/5

Answer 2

28/140

28 is divisible by 2, and so is 140 so

(28/140) / (2/2) = (14/70)

14 and 70 are divisible by 7... so

(14/70) / (7/7) = (2/10)

2 and 10 are both divisible by 2 so

(2/10) / (2/2) = (1/5)

1 and 5 are both prime numbers, you can't divide anymore
(they have no common factors)

If you divide any number by itself, you get 1

if you divide by 1, you get what you started with.

if you multiply or divide any fraction, by another fraction that has a value of 1, then you get the same fraction

any fraction that is the same one the top and bottom, then it is a 1

1/5 *2/2 = 2/10
2/10 is the same as 1/5

lowest terms is the point where you can no longer divide by fraction with the value of one(except 1/1), and have whole numbers in the numerator and denominator
2/13 is in lowest terms, try to divide by 1 as 2/2 you get
1/6.5 that is an improper fraction because of the 6.5
no decimals allowed!

Answer 3

to find the lowest term for 28/140. first factor the number into it's prime number components. Prime numbers, of course, can only be divided by themselves or 1 without any remainders. i.e. 2,3,5,7,11,13,17,19,23, etc.

2*2*7 =28
and
2*2*5*7 = 140

2*2*7 will divide into 2*2*7 1 time, leaving the five as the denominator

1/5 is the answer. 28 is 1/5 of 140

Answer 4

In middle school near here they teach the children this algorithm:
Try to divide the numerator (the top number) and the denominator by successive integers, starting with two. When the division produces integer quotients ("when they divide evenly"), write those quotients down as a new fraction, and start over again on the new fraction with two.

Of course, skipping successive integers that are non-prime may get you there faster, but these students are just getting started with factoring and the problems are fairly rudimentary.

On a related note, did you know that the Fundamental Theorem of Arithmetic states that "every natural number greater than 1 can be written as a unique product of prime numbers"?

(Oops! Am I cheating by asking a question in an answer?)

Answer 5

if both the numbers have nothing in common at all, then that's it.................... what do i mean with "nothing in common"? well, suppose u have the numbers 28 and 140..... the very first thing i noticed about them is that they can both be divided by 2.... but when i dig some more, i see that they're also both divisible by 4.... but i dont stop... now i see that they're both divisible ny 7, hey.... and also 14... wait a minute, they're both divisible by 28 too.... So now that i figured out what's theie greatest common factor (GCF) is ... so now, i'll divide both numbers by that gcf... i get 1/5

more examples:


1) 54/90 (well i see that 9 might be the GCF so i try diviving both sides by 9) i get 6/10

(but 6 and ten still have something in common,,,, they can both be divided by two)
i get 2/5 (that's the final answer, u cant do anything with 2 and 5 to reduce them)


2) 18/6 (gcf=6) (this one's easy) = 3/1 or jus simply 3.


did i help somehow?

Answer 6

keep dividing both the numerator and denominator by all the common factors you can find. for example, 5/10 - both numbers are multiples of five, so wen u divide, you get 1/2

28 and 140 are both divisible by 28, so 28/140 = 1/5

Answer 7

You take a factor (a number that both can be divided by equally) that both the numerator (top number) and the denomanator (bottom number) share. You divide them. Keep doing this until you cannot find any more common factors.

For example:
28 divided by 2= 14 divided by 2= 7 divided by 7= 1
140 divided by 2= 70 divided by 2= 35 divided by 7= 5

The simplist form is 1 over 5.

----OR----

28 divide by 4= 7 divided by 7= 1
140 divide by 4= 35 divided by 7= 5

The simplist form is still 1 over 5.

Answer 8

just make sure you can't devide the numerator and the denominator by the same number. If you can, the fraction can be reduced.

100/1000 = 10/100 = 1/10