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Use fraction tiles to find equivalent fractions: How many eighths equal one-fourth?

2

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Use fraction tiles to find equivalent fractions: How many twelfths equal one-fourth?

3

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Find equivalent fractions

We used fraction tiles to show that there are many fractions equivalent to 1 2 . For example, 2 4 , 3 6 , and 4 8 are all equivalent to 1 2 . When we lined up the fraction tiles, it took four of the 1 8 tiles to make the same length as a 1 2 tile. This showed that 4 8 = 1 2 . See [link] .

We can show this with pizzas, too. [link] (a) shows a single pizza, cut into two equal pieces with 1 2 shaded. [link] (b) shows a second pizza of the same size, cut into eight pieces with 4 8 shaded.

Two pizzas are shown. The pizza on the left is divided into 2 equal pieces. 1 piece is shaded. The pizza on the right is divided into 8 equal pieces. 4 pieces are shaded.

This is another way to show that 1 2 is equivalent to 4 8 .

How can we use mathematics to change 1 2 into 4 8 ? How could you take a pizza that is cut into two pieces and cut it into eight pieces? You could cut each of the two larger pieces into four smaller pieces! The whole pizza would then be cut into eight pieces instead of just two. Mathematically, what we’ve described could be written as:

1 times 4 over 2 times 4 is written with the 4s in red. This is set equal to 4 over 8.

These models lead to the Equivalent Fractions Property, which states that if we multiply the numerator and denominator of a fraction by the same number, the value of the fraction does not change.

Equivalent fractions property

If a , b , and c are numbers where b 0 and c 0 , then

a b = a · c b · c

When working with fractions, it is often necessary to express the same fraction in different forms. To find equivalent forms of a fraction, we can use the Equivalent Fractions Property. For example, consider the fraction one-half.

The top line says that 1 times 3 over 2 times 3 equals 3 over 6, so one half equals 3 sixths. The next line says that 1 times 2 over 2 times 2 equals 2 over 4, so one half equals 2 fourths. The last line says that 1 times 10 over 2 times 10 equals 10 over 20, so one half equals 10 twentieths.

So, we say that 1 2 , 2 4 , 3 6 , and 10 20 are equivalent fractions.

Find three fractions equivalent to 2 5 .

Solution

To find a fraction equivalent to 2 5 , we multiply the numerator and denominator by the same number (but not zero). Let us multiply them by 2 , 3 , and 5 .

On the left, we see that 2 times 2 over 5 times 2 equals 4 over 10. In the middle, we see that 2 times 3 over 5 times 3 equals 6 over 15. On the right, we see that 2 times 5 over 5 times 5 equals 10 over 25.

So, 4 10 , 6 15 , and 10 25 are equivalent to 2 5 .

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Find three fractions equivalent to 3 5 .

Correct answers include 6 10 , 9 15 , and 12 20 .

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Find three fractions equivalent to 4 5 .

Correct answers include 8 10 , 12 15 , and 16 20 .

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Find a fraction with a denominator of 21 that is equivalent to 2 7 .

Solution

To find equivalent fractions, we multiply the numerator and denominator by the same number. In this case, we need to multiply the denominator by a number that will result in 21 .

Since we can multiply 7 by 3 to get 21 , we can find the equivalent fraction by multiplying both the numerator and denominator by 3 .

2 over 7 equals 2 time 3 over 7 times 3. The 3s are shown in red. This is set equal to 6 over 21.

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Find a fraction with a denominator of 21 that is equivalent to 6 7 .

18 21

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Find a fraction with a denominator of 100 that is equivalent to 3 10 .

30 100

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Locate fractions and mixed numbers on the number line

Now we are ready to plot fractions on a number line. This will help us visualize fractions and understand their values.

Doing the Manipulative Mathematics activity "Number Line Part 3 " will help you develop a better understanding of the location of fractions on the number line.

Let us locate 1 5 , 4 5 , 3 , 3 1 3 , 7 4 , 9 2 , 5 , and 8 3 on the number line.

We will start with the whole numbers 3 and 5 because they are the easiest to plot.

A number line is shown with the numbers 3, 4, and 5. There are red dots at 3 and at 5.

The proper fractions listed are 1 5 and 4 5 . We know proper fractions have values less than one, so 1 5 and 4 5 are located between the whole numbers 0 and 1 . The denominators are both 5 , so we need to divide the segment of the number line between 0 and 1 into five equal parts. We can do this by drawing four equally spaced marks on the number line, which we can then label as 1 5 , 2 5 , 3 5 , and 4 5 .

Questions & Answers

how did you get 1640
Noor Reply
If auger is pair are the roots of equation x2+5x-3=0
Peter Reply
Wayne and Dennis like to ride the bike path from Riverside Park to the beach. Dennis’s speed is seven miles per hour faster than Wayne’s speed, so it takes Wayne 2 hours to ride to the beach while it takes Dennis 1.5 hours for the ride. Find the speed of both bikers.
MATTHEW Reply
420
Sharon
from theory: distance [miles] = speed [mph] × time [hours] info #1 speed_Dennis × 1.5 = speed_Wayne × 2 => speed_Wayne = 0.75 × speed_Dennis (i) info #2 speed_Dennis = speed_Wayne + 7 [mph] (ii) use (i) in (ii) => [...] speed_Dennis = 28 mph speed_Wayne = 21 mph
George
Let W be Wayne's speed in miles per hour and D be Dennis's speed in miles per hour. We know that W + 7 = D and W * 2 = D * 1.5. Substituting the first equation into the second: W * 2 = (W + 7) * 1.5 W * 2 = W * 1.5 + 7 * 1.5 0.5 * W = 7 * 1.5 W = 7 * 3 or 21 W is 21 D = W + 7 D = 21 + 7 D = 28
Salma
Devon is 32 32​​ years older than his son, Milan. The sum of both their ages is 54 54​. Using the variables d d​ and m m​ to represent the ages of Devon and Milan, respectively, write a system of equations to describe this situation. Enter the equations below, separated by a comma.
Aaron Reply
find product (-6m+6) ( 3m²+4m-3)
SIMRAN Reply
-42m²+60m-18
Salma
what is the solution
bill
how did you arrive at this answer?
bill
-24m+3+3mÁ^2
Susan
i really want to learn
Amira
I only got 42 the rest i don't know how to solve it. Please i need help from anyone to help me improve my solving mathematics please
Amira
Hw did u arrive to this answer.
Aphelele
hi
Bajemah
-6m(3mA²+4m-3)+6(3mA²+4m-3) =-18m²A²-24m²+18m+18mA²+24m-18 Rearrange like items -18m²A²-24m²+42m+18A²-18
Salma
complete the table of valuesfor each given equatio then graph. 1.x+2y=3
Jovelyn Reply
x=3-2y
Salma
y=x+3/2
Salma
Hi
Enock
given that (7x-5):(2+4x)=8:7find the value of x
Nandala
3x-12y=18
Kelvin
please why isn't that the 0is in ten thousand place
Grace Reply
please why is it that the 0is in the place of ten thousand
Grace
Send the example to me here and let me see
Stephen
A meditation garden is in the shape of a right triangle, with one leg 7 feet. The length of the hypotenuse is one more than the length of one of the other legs. Find the lengths of the hypotenuse and the other leg
Marry Reply
how far
Abubakar
cool u
Enock
state in which quadrant or on which axis each of the following angles given measure. in standard position would lie 89°
Abegail Reply
hello
BenJay
hi
Method
I am eliacin, I need your help in maths
Rood
how can I help
Sir
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Amoon
however, may I ask you some questions about Algarba?
Amoon
hi
Enock
what the last part of the problem mean?
Roger
The Jones family took a 15 mile canoe ride down the Indian River in three hours. After lunch, the return trip back up the river took five hours. Find the rate, in mph, of the canoe in still water and the rate of the current.
cameron Reply
Shakir works at a computer store. His weekly pay will be either a fixed amount, $925, or $500 plus 12% of his total sales. How much should his total sales be for his variable pay option to exceed the fixed amount of $925.
mahnoor Reply
I'm guessing, but it's somewhere around $4335.00 I think
Lewis
12% of sales will need to exceed 925 - 500, or 425 to exceed fixed amount option. What amount of sales does that equal? 425 ÷ (12÷100) = 3541.67. So the answer is sales greater than 3541.67. Check: Sales = 3542 Commission 12%=425.04 Pay = 500 + 425.04 = 925.04. 925.04 > 925.00
Munster
difference between rational and irrational numbers
Arundhati Reply
When traveling to Great Britain, Bethany exchanged $602 US dollars into £515 British pounds. How many pounds did she receive for each US dollar?
Jakoiya Reply
how to reduced echelon form
Solomon Reply
Jazmine trained for 3 hours on Saturday. She ran 8 miles and then biked 24 miles. Her biking speed is 4 mph faster than her running speed. What is her running speed?
Zack Reply
d=r×t the equation would be 8/r+24/r+4=3 worked out
Sheirtina
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Source:  OpenStax, Prealgebra. OpenStax CNX. Jul 15, 2016 Download for free at http://legacy.cnx.org/content/col11756/1.9
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