using lowest common denominator to add and subtract fractions
DESCRIPTION
Using Lowest Common Denominator to add and subtract fractions. Mr. Coon’s Math Class. Product. 6 X 6 = 36. The answer to a multiplication problem. What is the product?. 7 X 8 = 56. What is the product?. 8 X 9 = 72. Multiple. Some multiples of 6 6, 12, 18, 24, 30, 36, 42. - PowerPoint PPT PresentationTRANSCRIPT
Mr. Coon’s Math Class
The answer to a multiplication problem.
6 X 6 = 36
7 X 8 = 56
8 X 9 = 72
The product of a whole number multiplied times any other whole number.
Some multiples of 6 6, 12, 18, 24, 30, 36, 42
5, 10, 15, 20, 25, 30, 35
7, 14, 21, 28, 35, 42, 49
4, 8, 12, 16, 20, 24, 28
9, 18, 27, 36, 45, 54, 63
A number that is a multiple of two or more numbers.
Some multiples of 3 & 6
6, 12, 18, 24, 30, 36, 42
8, 16, 24, 32, 40, 48, 56
12, 24, 36, 48, 56, 60
21, 42, 63
10, 20, 30, 40, 50, 60
The smallest common multiple of a set of two or more numbers.
6 = 6, 12, 18, 24, 30, 36
5 = 5, 10, 15, 20, 25, 30
8 = 8, 16, 24, 32, 40, 48 3 = 3, 6, 9, 12, 15, 21, 24
8 = 8, 16, 24, 32, 40, 48 4 = 4, 8, 12, 16, 20, 24
8 = 8, 16, 24, 32, 40, 48 6 = 6, 12, 18, 24, 30, 36
10 = 10, 20, 30, 40, 50, 4 = 4, 8, 12, 16, 20, 24
9 = 9, 18, 27, 36, 45, 54 3 = 3, 6, 9, 12, 15, 21,
Find the multiples of each denominator.
1= 5, 10, 15, 20, 25, 30
1= 10, 20, 30, 40, 50+
5
10
Compare the lists of multiples. Circle the common multiples between the two lists.
15 = 5, 10, 15, 20, 25, 301
10 = 10, 20, 30, 40, 50+
Use the lowest common multiple as the denominator.
15 = 5, 10, 15 ,20 ,25 ,301
10 = 10, 20, 30, 40, 50+
This number is also called the least common denominator.
15 = 5, 10, 15 ,20 ,25 ,301
10 = 10, 20, 30, 40, 50+
12 = 2, 4, 6, 8, 10, 1218 = 8, 16, 24, 32, 40+
110 = 10, 20, 30, 40, 18 = 8, 16, 24, 32, 40+
110 = 10, 20, 30, 40, 14 = 4, 8, 12, 16, 20, +
12 = 2, 4, 6, 8, 10, 14 = 4, 8, 12, 16, 20, +
12 = 2, 4, 6, 8, 10, 12 112 = 12, 24, 36, 48 +
13 = 3, 6, 9, 12, 15 14 = 4, 8, 12, 16, 20, +
13 = 3, 6, 9, 12, 15 15 = 5, 10, 15, 20, 25, +
13 = 3, 6, 9, 12, 15 19 = 9, 18, 27, 36, 45, +
1319+
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.
3 will divide evenly into 9, so 9 is your LCD or LCM.
1214+
Using the shortcut, what is the LCD or LCM?
2 will divide evenly into 4, so 4 is your LCD or LCM.
12110+
Using the shortcut, what is the LCD or LCM?
2 will divide evenly into 10, so 10 is your LCD or LCM.
12112+
Using the shortcut, what is the LCD or LCM?
2 will divide evenly into 12, so 12 is your LCD or LCM.
1418+
Using the shortcut, what is the LCD or LCM?
4 will divide evenly into 8, so 8 is your LCD or LCM.
1316+
Using the shortcut, what is the LCD or LCM?
3 will divide evenly into 6, so 6 is your LCD or LCM.
13112+
Using the shortcut, what is the LCD or LCM?
3 will divide evenly into 12, so 12 is your LCD or LCM.
13115+
Using the shortcut, what is the LCD or LCM?
3 will divide evenly into 15, so 15 is your LCD or LCM.
1318+
Using the shortcut, what is the LCD or LCM?
3 will not divide evenly into 8, so find the least common multiple.