Subtracting Fractions
The most important thing that you must do before you subtract fractions is to make sure they have common denominators!
Examples:
2/5 - 1/5
I can subtract these two fractions together because they have the same denominator. I subtract the numerators (2 - 1) and keep the denominator. My answer is 1/5
2/4 -1/3
I can't subtract these two fractions because they do NOT have the same denominator. I MUST get common denominators!!
To get a common denominator I will multiply the 1/3 fraction by the other fraction's denominator (4). I will then multiply the 2/4 fraction by the other fraction's denominator (3). What ever I multiply the denominator by I MUST also multiply the numerator by the same number. So....my new fractions become 6/12-4/12 = 2/12. I ask myself "But wait....is there more??" Yes!! I can simplify! This fraction can be divided by 2. My final fraction is 1/6!
The most important thing that you must do before you subtract fractions is to make sure they have common denominators!
Examples:
2/5 - 1/5
I can subtract these two fractions together because they have the same denominator. I subtract the numerators (2 - 1) and keep the denominator. My answer is 1/5
2/4 -1/3
I can't subtract these two fractions because they do NOT have the same denominator. I MUST get common denominators!!
To get a common denominator I will multiply the 1/3 fraction by the other fraction's denominator (4). I will then multiply the 2/4 fraction by the other fraction's denominator (3). What ever I multiply the denominator by I MUST also multiply the numerator by the same number. So....my new fractions become 6/12-4/12 = 2/12. I ask myself "But wait....is there more??" Yes!! I can simplify! This fraction can be divided by 2. My final fraction is 1/6!