I'm very far behind in mathematics mainly because of my lack of ability to pay attention to it or understand it. I hope that through the help of this website I'll know all the math I need to function in American society.
-
Fractions:
1. Add: First you have to make sure both denominators are the same. So lets say 1/2 and 1/3. Since both denominators are 3 and 2, the lowest common multiple is 6. So you try to change the denominator to 6. You multiply 1/2 by 3, it becomes 3/6, and then you multiply 1/3 by 2, it becomes 2/6. 2/6 + 3/6 = 5/6.
2. Subtract: The same rule applies: Make sure both fraction's denominators are the same! Say 2/4 minus 2/6. Make the denominator the lowest common multiple of both numbers, which is 24. So 2/6 x 4 = 8/24 and 2/4 x 6 = 12/24. So 12/24 minus 8/24 becomes 4/24 and you can reduce that to 1/6 :)
3. Multiply: this is the easiest. Say 1/6 times 4/5. You just times it per normal; Numerator times numerator, and denominator times denominator. 1x4=4, and 6x5=30. So it becomes 4/30!
4. Divide: This is a little tricky. Example 5/6 and 7/3. Everytime you divide, you change the sign to a multiply and flip one of the fractions. Therefore, 5/6 ÷ 7/3 = 5/6 x 3/7. And you apply the same multiplication rules for fractions. Numerator times numerator and denominator times denominator! So the answer becomes 15/42. Reduce it and it becomes 5/14.
Decimals:
Add: This is really simple. Say 10.3 + 11.9, just do it as per normal. 10+11 = 21, 0.3+0.9 = 1.1 So 1.1+21 = 22.1 :)
Subtract: Same thing. say 15.6 - 8.4, 15 - 8 = 7, 0.6 - 0.4 = 0.2, 7 + 0.2 = 7.2.
Multiply: honestly up till here decimals work the same as whole numbers, if not you can change them to fractions! Example 4.5 x 8.9. You have to the working! Sorry i can't type and explain the working here :/ But you can change them to fraction form. 45/10 and 89/10. Multiply them as per normal, and it becomes 40.05.
1. Add: First you have to make sure both denominators are the same. So lets say 1/2 and 1/3. Since both denominators are 3 and 2, the lowest common multiple is 6. So you try to change the denominator to 6. You multiply 1/2 by 3, it becomes 3/6, and then you multiply 1/3 by 2, it becomes 2/6. 2/6 + 3/6 = 5/6.
2. Subtract: The same rule applies: Make sure both fraction's denominators are the same! Say 2/4 minus 2/6. Make the denominator the lowest common multiple of both numbers, which is 24. So 2/6 x 4 = 8/24 and 2/4 x 6 = 12/24. So 12/24 minus 8/24 becomes 4/24 and you can reduce that to 1/6 :)
3. Multiply: this is the easiest. Say 1/6 times 4/5. You just times it per normal; Numerator times numerator, and denominator times denominator. 1x4=4, and 6x5=30. So it becomes 4/30!
4. Divide: This is a little tricky. Example 5/6 and 7/3. Everytime you divide, you change the sign to a multiply and flip one of the fractions. Therefore, 5/6 ÷ 7/3 = 5/6 x 3/7. And you apply the same multiplication rules for fractions. Numerator times numerator and denominator times denominator! So the answer becomes 15/42. Reduce it and it becomes 5/14.
Decimals:
Add: This is really simple. Say 10.3 + 11.9, just do it as per normal. 10+11 = 21, 0.3+0.9 = 1.1 So 1.1+21 = 22.1 :)
Subtract: Same thing. say 15.6 - 8.4, 15 - 8 = 7, 0.6 - 0.4 = 0.2, 7 + 0.2 = 7.2.
Multiply: honestly up till here decimals work the same as whole numbers, if not you can change them to fractions! Example 4.5 x 8.9. You have to the working! Sorry i can't type and explain the working here :/ But you can change them to fraction form. 45/10 and 89/10. Multiply them as per normal, and it becomes 40.05.
12
keywords: and,decimals,subtract,you,add,multiply,How,do,divide,fractions,How do you add,divide,subtract, and multiply fractions and decimals