Fraction Visualizer
Move the sliders to build each fraction, then compare them and see their sum — with matching pie and bar models.
About the Fraction Visualizer
Two sliders, two fractions, and two ways to see each one: a pie wedge and a divided bar, updating together as a student drags the numerator or denominator. Comparing 2/3 to 3/5 stops being a guessing game once both fractions are sitting on the screen as shaded shapes side by side.
Underneath the visuals, the tool runs the actual math: cross-multiplication for an exact greater-than, less-than, or equal comparison, and a fully reduced sum with the simplification already applied, shown as a mixed number when it's worth more than one whole.
How to use it in your classroom
- Set Fraction A's numerator and denominator with the two sliders.
- Set Fraction B the same way.
- Watch the pie and bar models for each fraction update as you adjust them.
- Read the comparison and sum at the bottom, which update live.
Tips from the classroom
- Hold one fraction's denominator fixed while changing the other to highlight why a common denominator makes comparison and addition so much easier.
- Project the pie and bar models side by side when introducing equivalent fractions, such as 1/2 and 2/4 — same shaded area, different denominator.
- The denominator slider tops out at 12, which conveniently covers halves, thirds, fourths, sixths, eighths, and twelfths in one tool.
- Use the sum panel to check a student's written answer to a fraction-addition problem instantly, without working it out by hand at their desk.
Frequently asked questions
Does the comparison use decimal approximations?
No, it cross-multiplies the two fractions, which gives an exact comparison rather than one that could be thrown off by rounding.
Is the sum shown in lowest terms?
Yes, the sum is reduced to its simplest form, and it's also shown as a mixed number whenever the result is more than one whole.
Can the denominator go higher than 12?
Not with the slider as configured. Twelve covers the most commonly taught denominators in elementary and middle grades.