Fraction Builder: Compare, Add & Equivalent Fractions
Build two fractions with bars, circles and a number line, compare them, find equivalent fractions and add them.
Build two fractions. Click the pieces of a bar to fill or empty them, or use the sliders. See them as bars, circles and on the number line, compare them and add them.
About the Fraction Builder: Compare, Add & Equivalent Fractions
Free fraction builder: compare, add & equivalent fractions. Build two fractions with bars, circles and a number line, compare them, find equivalent fractions and add them. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for math, the fraction builder: compare, add & equivalent fractions runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Build two fractions with bars, circles and a number line, compare them, find equivalent fractions and add them. Use it to explore math ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Fraction Builder: Compare, Add & Equivalent Fractions
- Use the controls to change First: numerator, First: denominator, Second: numerator, Second: denominator, Picture. The simulation reacts instantly.
- Pick an option such as Bars, Circles to switch modes or load an example.
- Press "Make equivalent", "Random pair" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Make 1/2 and use Make equivalent to see 2/4.
- Compare 3/8 and 2/5 with the bars.
- Add 1/3 and 1/4 and read the sum.
- Find two different fractions that both equal 0.75.
Key ideas you can learn
- A fraction names equal parts of a whole: the denominator says how many parts, the numerator how many are shaded.
- Equivalent fractions name the same amount, like 1/2 and 2/4.
- Fractions on a number line show which is bigger.
- To add fractions you first need pieces of the same size.
Where this is used in the real world
Cooking, measuring, money, music rhythms and construction all use fractions every day.
Who is this simulation for?
Algebra, geometry, trigonometry and calculus students, teachers preparing demonstrations, and self-learners who want to see the maths move.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
How do you compare two fractions?
Compare their size on the bar or number line, or convert both to the same denominator.
What are equivalent fractions?
Different fractions with the same value, made by multiplying the numerator and denominator by the same number.
Is the Fraction Builder: Compare, Add & Equivalent Fractions free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Fraction Builder: Compare, Add & Equivalent Fractions work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.