Keep the whole the same
Compare fractions using bars with the same total length.
Fraction Builder
Build fractions with equal pieces and find different ways to cover the same part of a whole.
Grades 3–5 · Math
Your goal
Build 1/2 of a whole.
Reduced motion is on. The controls still update the scene.
You built 0/4. Each piece is 1/4 of the same-sized whole.
Both rows use identical whole sizes. Choosing a new part size clears your pieces.
Related resources
Related simulations
Common mistakes to avoid
Related tools
Learn with Fraction Builder
Fraction Builder gives elementary students a visual way to understand equal parts, numerators, denominators, and equivalent fractions. Choose how many equal pieces divide a whole, then add or remove pieces to match a target amount. The bars always use the same whole size, so children can compare fractions fairly. Building the same amount with different divisions helps learners explain why fractions such as one half and two fourths represent equal quantities, even though their numerators and denominators differ.
What to look for
Count equal pieces
The denominator tells how many equal parts make one whole. The numerator counts the selected parts.
Look for a match
Two fractions are equivalent when they cover the same amount of the same-sized whole.
For teachers and curious learners
Understand equal parts and equivalent fractions. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Each bar represents one whole of equal size. Only equal divisions are used, and equivalence is checked using exact integer arithmetic.
Continue with Fraction Wall .