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Course: Grade 5 math (FL B.E.S.T.) > Unit 4
Lesson 6: Adding and subtracting fractions with unlike denominators word problemsAdd and subtract fractions: FAQ
Frequently asked questions about adding and subtracting fractions.
How do we estimate fractions to add or subtract them?
One way to estimate fractions is to round them to the nearest half or whole number. For example, rounds to , and rounds to .
Try it yourself with this exercise:
How do you add and subtraction fractions visually?
To add or subtract fractions, they need to have the same denominator. We can use fraction bars to visually compare the fractions so we can add and subtract.
Try it yourself with this exercise:
What's the difference between adding and subtracting fractions with like denominators and adding and subtracting fractions with unlike denominators?
When the denominators are the same, we can add or subtract the numerators directly. When the denominators are different, we need to find a common denominator first.
Try it yourself with these exercises:
How do we find common denominators?
There are a few different ways to find common denominators. One way is to use the least common multiple (LCM) of the two denominators. Another way is to just multiply the two denominators together.
Try it yourself with these exercises:
What are mixed numbers and how do we add and subtract them?
Mixed numbers are numbers that contain both a whole number and a fraction. For example, is a mixed number.
To add and subtract them, we have to find a common denominator. Then, we rewrite the mixed numbers as improper fractions with that denominator. Lastly, we add or subtract the two improper fractions together and simplify the result if needed.
Try it yourself with these exercises:
Want to join the conversation?
- how to regroup mixed numbers and what is regrouping?(10 votes)
- How are you supposed to solve a fraction problem where you are taking away a smaller number from a bigger one. Take this example.
1/2-2/5
You cannot take 2 away from 1 without getting a negative number, but 2/5 is smaller then 1/2, so how do you solve the problem.(4 votes) - how do you regroup t improper fractions(4 votes)
- It's the Least Common Multiple. It's like the smallest multiple that two or more numbers have in common.(6 votes)
- Thank you so much for this! It helped a lot! But my only question is does this require LCD?(3 votes)
- So, if mixed numbers are numbers that contain both a whole number and a fraction, how do we multiply and divide them?
After this question, try experimenting with different numbers and find the least common denominator to those numbers.
(2 votes) - LCM is when you try to make two different denominator into same denominator. For example: What is 2/3 + 2/4? then the answer will equal to 6/12 + 8/12. Answer=14/12.(2 votes)
- How does 2/3 round to 1/2 and 7/8 round to 1? I need help in this please comment(1 vote)
- how does the lcd become the lcd(1 vote)
- What is LCD? Does it stand for something?(1 vote)