Mixed Numbers Mixed numbers are whole numbers and fractions together. 1 3 2
Subtracting Mixed Numbers To subtract mixed numbers, you must make sure the fractions have the same denominator, that’s the same bottom number. Find the lowest common multiple of the two denominators. That is the number you will use for the denominator in both fractions.
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 Subtract Mixed Numbers With Unlike Denominators Find the multiples of each denominator. 1 3 4 = 4, 8, 12, 16, 20, 24 1 1 - 10 = 10, 20, 30, 40, 50
To Subtract Mixed Numbers 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 Subtract Mixed Numbers 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 Subtract Mixed Numbers 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 Subtract Mixed Numberss 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 Subtract Mixed Numbers 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 Subtract Mixed Numberss 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 Subtract Mixed Numbers 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 Subtract Mixed Numbers 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 Subtract Mixed Numbers With Unlike Denominators Now just subtract the numerators. 1 5 x 5 = 3 4 20 x 5 = 1 2 x 2 = Remember! We never subtract the denominators. 1 - 10 20 x 2 = 3 20
To Subtract Mixed Numbers With Unlike Denominators Now subtract the whole numbers. 1 5 x 5 = 3 4 20 x 5 = 1 2 x 2 = 1 - 10 20 x 2 = 3 2 20
Subtract These Mixed Numbers Use the short cut to find the Least Common Denominator (LCD). 1 10 3 6 1 3 - 6 6
Subtract These Mixed Numbers 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.
Subtract These Mixed Numbers 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
Subtract These Mixed Numbers 1 2 Now multiply across. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 - 6 x 1 = 6
Subtract These Mixed Numbers 1 2 Subtract your new numerators. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 - 6 x 1 = 6 1 6
Subtract These Mixed Numbers 1 2 Subtract your whole numbers. x 2 = 10 3 6 x 2 = 1 1 x 1 = 3 - 6 x 1 = 6 1 7 6
Subtract These Mixed Numbers 1 2 Your answer is: x 2 = 10 3 6 x 2 = 1 1 x 1 = 1 3 - 6 x 1 = 6 7 6