Magnetic Fraction Slices Teaching Aid

Magnetic Fraction Slices is a hands-on classroom maths aid designed to help learners visualise and compare common fractions.

Each fraction set forms a complete “pie”, with individual slices labelled on top. The set includes:

• 1/2

• 1/3

• 1/4

• 1/5

• 1/6

• 1/7

• 1/8

• 1/9

• 1/10

The slices are designed to be used on a magnetic board, fridge, whiteboard, or any magnetic teaching surface. A separate base ring is included to help keep the slices neatly aligned when building a full pie.

This is useful for teaching:

• Equivalent fractions

• Fraction comparison

• Parts of a whole

• Numerator and denominator concepts

• Addition and subtraction of simple fractions

• Visual fraction grouping

I printed each fraction size in a different colour to make them easier for young learners to identify and sort.

Features

• Magnetic fraction slices for classroom or home learning

• Includes common fractions from halves to eighths

• Engraved fraction labels on each slice

• Separate base ring to help assemble the full pie

• Each slice and ring is provided as a separate STL

• No supports required

• Simple PLA print

• Magnet holes included for easy post-print assembly

Files Included

The model includes separate STL files for the fraction slices and the base ring.

Fraction sets included:

Print Settings

These are the settings I used:

The fractions are engraved on the top face of each slice, which is printed against the build plate.

The magnet holes are on the bottom of the pieces and face upward while printing.

Magnets

Each slice uses:

• 1 × 2 mm × 5 mm magnet

The base ring uses:

• 3 × 2 mm × 5 mm magnets

I glued the magnets in place after printing using superglue.

Before gluing, check the magnet polarity so that all pieces attach correctly to your magnetic surface.

Assembly

1. Print the required fraction slices and base ring.

2. Test-fit the magnets before gluing.

3. Add a small amount of superglue into each magnet hole.

4. Press the magnets into place.

5. Allow the glue to cure fully before using the pieces.

6. Use the base ring to help learners assemble a complete fraction pie.

Colour Suggestions

I printed each fraction size in a different colour, which works very well for teaching and sorting.

You can obviously use any colour scheme you prefer.

Edit - coloured in the text with a permanent marker.  

Classroom Use Ideas

Use the slices to ask learners questions like:

• How many quarters make one whole?

• Which is bigger: 1/3 or 1/4?

• Can you build one whole using only eighths?

• Can you show the same amount using different fraction pieces?

• What happens when one slice is removed?

Because the pieces are magnetic, they work nicely for demonstrations on a board in front of a class.

Notes: This was designed as a simple, practical teaching aid for early fraction learning. The pieces are easy to print, quick to assemble, and robust enough for classroom use.

It was inspired by Fraction Blocks by ImproperSubset

Please share your makes, remixes, and classroom setups — I would love to see how others use it.