Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator.

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy.

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy. EXAMPLE # 1 : Find the lowest common factor of 2 and 5.

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy. EXAMPLE # 1 : Find the lowest common factor of 2 and 5. Factors of 22, 4, 6, 8, 10, 12, 14, 16, 18, 20, … Factors of 55, 10, 15, 20, 25, 30, 35, 40, …

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy. EXAMPLE # 1 : Find the lowest common factor of 2 and 5. Factors of 22, 4, 6, 8, 10, 12, 14, 16, 18, 20, … Factors of 55, 10, 15, 20, 25, 30, 35, 40, … As you can see, the lowest common factor is 10, which will be the common denominator

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy. EXAMPLE # 2 : Find the lowest common factor of 3 and 7.

Fractions – Common Denominators When adding and subtracting fractions you need a common denominator. This section will focus on finding the lowest common denominator. Lowest common denominator is also the lowest common multiple or factor of two or more numbers. Listing the factors of each number and then finding the smallest common one is one strategy. EXAMPLE # 2 : Find the lowest common factor of 3 and 7. Factors of 33, 6, 9, 12, 15, 18, 21, 24, 27, 30, … Factors of 77, 14, 21, 28, 35, 42, 49, 56, … As you can see, the lowest common factor is 21, which will be the common denominator

Fractions – Common Denominators There is a short cut to these but you might have to reduce later in the problem. Just multiply the two numbers together to get the common denominator. In some cases it will be the first common factor they will share.

Fractions – Common Denominators There is a short cut to these but you might have to reduce later in the problem. Just multiply the two numbers together to get the common denominator. In some cases it will be the first common factor they will share. EXAMPLE # 3 : Find the lowest common factor between 4 and 9.

Fractions – Common Denominators There is a short cut to these but you might have to reduce later in the problem. Just multiply the two numbers together to get the common denominator. In some cases it will be the first common factor they will share. EXAMPLE # 3 : Find the lowest common factor between 4 and 9. 4 x 9 = 36 Factors of 44, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, … Factors of 99, 18, 27, 36, 45, 54, 63, 72, …

Fractions – Common Denominators There is a short cut to these but you might have to reduce later in the problem. Just multiply the two numbers together to get the common denominator. In some cases it will be the first common factor they will share. EXAMPLE # 3 : Find the lowest common factor between 4 and 9. 4 x 9 = 36 Factors of 44, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, … Factors of 99, 18, 27, 36, 45, 54, 63, 72, … EXAMPLE # 4 :Find the lowest common factor between 2, 3 and 9.

Fractions – Common Denominators There is a short cut to these but you might have to reduce later in the problem. Just multiply the two numbers together to get the common denominator. In some cases it will be the first common factor they will share. EXAMPLE # 3 : Find the lowest common factor between 4 and 9. 4 x 9 = 36 Factors of 44, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, … Factors of 99, 18, 27, 36, 45, 54, 63, 72, … EXAMPLE # 4 :Find the lowest common factor between 2, 3 and 9. Factors of 22, 4, 6, 8, 10, 12, 14, 16, 18, 20 Factors of 33, 6, 9, 12, 15, 18, 21, 24, 27, 30 Factors of 99, 18, 27, 36, 45, 54, 63, 72, 81, 90 Answer is 18