Fraction Insets (Fraction Circles)
Fraction insets are ten frames holding circles cut into halves and on to tenths, used from about 4.5 to name the parts of a whole. On October 5, 2026 they cost $56.95 for a wooden set and $194.40 to $319.90 for metal at the US sellers we checked. Card circles cover the first lessons.
The first lesson with it is Fraction Insets (Fraction Circles). Not sure your child is ready for it? Two minutes of questions place your child on the sequence.
| Area | Math |
|---|---|
| Used in | |
| From age | 4.5 to 7 years |
| Make it | Possible to make with some effort |
| Buy it | About $57 to $320 (noted ) |
What the fraction insets (fraction circles) is for
The child lifts the pieces of one circle out, traces them, fits them back, and learns their names: one half, one third, one fourth. Later the child fills one circle with pieces from different frames and finds that two fourths take the place of one half.
Montessori's 1917 book describes ten metal plates with circles 10 cm across, whole to tenths. She used them with older children for writing and reducing fractions.
| Part | What it looks like |
|---|---|
| Frames | Ten, each with a round opening 10 cm across |
| Pieces | One whole circle, then circles cut into 2 to 10 equal sectors, each with a small knob |
| Colors | Montessori Outlet's wooden set has red pieces in green frames |
| Stands | Included with Alison's metal and wooden sets; sold separately by Nienhuis; none with Montessori Outlet's |
The lessons that use the fraction insets (fraction circles)
Fraction Insets (Fraction Circles)
4.5 to 7 yearsLifting the pieces of a circle cut into halves, thirds, fourths and on to tenths out of their frames, fitting them back, and learning the names of the parts.
Buying one: 4 listings checked October 5, 2026
| Seller and set | Made of | Price |
|---|---|---|
| Montessori OutletWooden Fraction Circles (510500640)Wooden version. Sale price; regular $290.80. Ten circles, whole to tenths. No stand. In stock. | Wood; red insets, green frames | $56.95 |
| Alison's MontessoriMetal Fraction Circles with Stands, 1/1 to 1/10 (M55)Sale price; regular $216.00. Ten circles with stands. Made in Thailand. | Metal frames and insets, wooden stands | $194.40 |
| Alison's MontessoriWooden Fraction Circles, Premium Quality (PM42)Wooden version. Ten frames and circles with two sloping stands. Made in Sri Lanka. | Russian birch, hand-painted | $259.00 |
| NienhuisFraction Circles (011400)Ten circles, whole to tenths. Stand sold separately. | Metal | $319.90 |
- Metal is the classic material and the heaviest. Alison's metal set at $194.40 includes stands; Nienhuis's at $319.90 doesn't.
- Montessori Outlet's wooden set at $56.95 is the cheapest by far. It does the naming lessons well, though it comes without a stand.
- Check that every circle fills with no gap and that the pieces lift out without sticking.
- Montessori Services and The Montessori Room had no fraction circles when we looked; The Montessori Room sells fraction skittles, a different material.
Making the fraction insets (fraction circles) at home
What to gather
- Thick card or 3 mm craft plywood
- A compass and a protractor
- A craft knife and a cutting mat
- Small wooden beads and glue, for knobs
| Piece | Size and marking | How many |
|---|---|---|
| Frames | 12 by 12 cm, two layers, a 10 cm circle cut from the top layer | 3 to start |
| Circles | 10 cm across: one whole, one cut into halves, one into fourths | 3 |
- 1Draw three 10 cm circles and cut them out cleanly.
- 2Cut one into halves through the center, and one into fourths with two lines at right angles.
- 3Cut a 10 cm opening in the top layer of each frame and glue it to a plain backing card.
- 4Glue a bead to each piece as a knob, and check that every circle fills its frame with no gap.
- 5Add thirds (120 degrees each) and more frames later, using the protractor.
Keeping a full set on the shelf
- Keep the frames upright in a stand or flat in a box. A bent metal frame no longer holds its pieces.
- Store each frame with its own pieces, and count them back at the end.
Questions parents ask about the fraction insets (fraction circles)
What are Montessori fraction circles used for?
First for naming the parts of a whole, from about 4.5. Later, in the elementary years, for equivalent fractions and for adding them, as Montessori's 1917 book describes.
Are wooden fraction circles as good as metal?
For the naming lessons, yes, if the pieces fill each circle exactly. Metal is the classic material and lasts longer.
How many fraction circles are in a set?
Ten: one whole circle and nine more cut into 2 to 10 equal pieces.
Before the fraction insets (fraction circles), make sure the work before it is solid. The geometric cabinet (plane geometric insets) lesson lists the signs that a child is ready to move on.