# Fraction XI Adding Mixed Numbers With Unlike Denominators

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Fraction XI Adding Mixed Numbers With Unlike Denominators

Some multiples of 3 & 4 12, 24, 36, 48, Common Multiple
A number that is a multiple of two or more numbers. Some multiples of 3 & 4 12, 24, 36, 48,

Least Common Multiple The smallest common multiple of a set of two or more numbers. 4 = 4, 8, 12, 16, 20, 24, 28 5 = 5, 10, 15, 20, 25, 30

Mixed Numbers Mixed numbers are whole numbers and fractions together. 1 3 2

Shortcut for Finding the Least Common Denominator or Least Common Multiple
Check to see if the smaller denominator divides evenly into the larger denominator. If it does, use the larger denominator for your LCD or LCM. 1 3 2 will divide evenly into 8, so 8 is your LCD or LCM. 2 1 1 + 8

To Add Fractions Mixed Numbers With Unlike Denominators
Find the multiples of each denominator. 1 3 4 = 4, 8, 12, 16, 20, 30 1 1 + 10 = 10, 20, 30, 40, 50

To Add Mixed Fractions With Unlike Denominators
Compare the lists of multiples. Circle the common multiples between the two lists. 1 3 4 = 4, 8, 12, 16, 20, 24 1 1 + = 10, 20, 30, 40, 50 10

To Add Mixed Fractions With Unlike Denominators
Use the least common multiple as the denominator. 1 3 4 = 4, 8, 12, 16, 20, 24 1 1 + = 10, 20, 30, 40, 50 10

To Add Mixed Fractions With Unlike Denominators
This number is also called the least common denominator. 1 3 4 = 4, 8, 12, 16, 20, 24 1 1 + = 10, 20, 30, 40, 50 10

To Add Mixed Fractions With Unlike Denominators
Find the equivalent fractions for 1/4 & 1/10 with 20 as the denominator. Ask yourself what you multiply 4 by to get 20. 1 3 4 20 x 5 = 1 1 + 10 20

To Add Mixed Fractions With Unlike Denominators
Find the equivalent fractions for 1/4 & 1/10 with 20 as the denominator. That’s right 5. Since you are looking for the equivalent fraction you know the top number must also be multiplied by 5. 1 x 5 = 3 4 20 x 5 = 1 1 + 10 20

To Add Mixed Fractions With Unlike Denominators
Find the equivalent fractions for 1/4 & 1/10 with 20 as the denominator. 1 5 x 5 = To find the top number just multiply 1 x 5 to get your equivalent fraction. 3 4 20 x 5 = 1 1 + 10 20

To Add Mixed Fractions With Unlike Denominators
Find the equivalent fractions for 1/4 & 1/10 with 20 as the denominator. 1 5 x 5 = Now ask what you multiply the 10 by to get 20. 3 4 20 x 5 = 1 1 + 10 20 x 2 =

To Add Mixed Fractions With Unlike Denominators
Find the equivalent fractions for 1/4 & 1/10 with 20 as the denominator. That’s right 2. Since you are looking for the equivalent fraction you know the top number must also be multiplied by 2. 1 5 x 5 = 3 4 20 x 5 = 1 2 x 2 = 1 + 10 20 x 2 =

To Add Mixed Fractions With Unlike Denominators
Now just add the numerators. 1 5 x 5 = 3 4 20 x 5 = 1 2 x 2 = Remember! We never add the denominators. 1 + 10 20 x 2 = 7 20

To Add Mixed Fractions With Unlike Denominators
Now add the whole numbers. 1 5 x 5 = 3 4 20 x 5 = 1 2 x 2 = 1 + 10 20 x 2 = 7 4 20

Use the short cut to find the Least Common Denominator (LCD). 1 10 3 6 1 3 + 6 6

Now find the equivalent fractions for 1/3 & 1/6. 1 10 3 6 x 2 = 1 3 + 6 x 1 = 6 Ask what do you multiply 3 by to get 6 and what do you multiply 6 by to get 6.

Since you are writing equivalent fractions, now multiply the top numbers by the same number you did in the bottom. 1 x 2 = 10 3 6 x 2 = 1 x 1 = 3 + 6 x 1 = 6

1 2 Now multiply across. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 + 6 x 1 = 6

1 2 Add your new numerators. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 + 6 x 1 = 6 3 6

1 2 Add your whole numbers. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 + 6 x 1 = 6 3 13 6

Simplify Your Answer 3 ÷ 3 1 13 13 = 6 ÷ 3 2

Find the common multiples for 5 and 3. Write this number as your new denominator. 4 11 5 15 1 2 + 3 15

Ask yourself what you multiply the bottom number by to get 15. 4 11 5 15 x 3 = 1 2 + 3 x 5 = 15

Multiply the top number by the same number you did in the bottom. 4 x 3 = 11 5 15 x 3 = 1 x 5 = 2 + 3 x 5 = 15

Multiply across. 4 12 x 3 = 11 5 15 x 3 = 1 5 x 5 = 2 + 3 x 5 = 15

Now add your new numerators. 4 12 x 3 = 11 5 15 x 3 = 1 5 x 5 = 2 + 3 x 5 = 15 17 15

Change Your Improper Fraction to a Mixed Number
2 4 12 x 3 = 11 1 15 5 15 x 3 = 15) 17 1 5 x 5 = 2 15 + 3 x 5 = 15 2 17 15

2 1 4 12 x 3 = 11 1 15 5 15 x 3 = 15) 17 1 5 x 5 = 2 15 + 3 x 5 = 15 2 17 14 15