Shape sorting: how the skill grows from 15 to 36 months
Shape sorting means fitting shaped pieces through matching holes. It joins looking and hand movement: the child has to notice the shape, choose a hole and turn the piece until the edges line up.
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Shape sorting: the ladder, step by step
Pick the step that looks most like your child today. The next step and activities that practise it appear below.
No step picked yet. There is no wrong answer: pick the closest one.
Next step: Fits the circle. Pushes the round piece through the round hole, which works whichever way it is turned.
Activities that fit this step
- Turn-to-Fit Slot Box · 16–30 months · 5–12 min
- One Open Hole Shape Sorter · 17–27 months · 5–10 min
- Cardboard Box Circle and Square · 20–30 months · 5–10 min
Next step: Tries another hole. Presses a piece against the wrong hole, then moves to a different one without help.
Activities that fit this step
- Turn-to-Fit Slot Box · 16–30 months · 5–12 min
- One Open Hole Shape Sorter · 17–27 months · 5–10 min
- Cardboard Box Circle and Square · 20–30 months · 5–10 min
Next step: Turns the piece. Rotates a square or triangle in the hand until its corners line up with the hole.
Activities that fit this step
- Turn-to-Fit Slot Box · 16–30 months · 5–12 min
- One Open Hole Shape Sorter · 17–27 months · 5–10 min
- Cardboard Box Circle and Square · 20–30 months · 5–10 min
Next step: Chooses by looking. Glances from piece to holes and picks the right one on the first try.
Activities that fit this step
- Turn-to-Fit Slot Box · 16–30 months · 5–12 min
- One Open Hole Shape Sorter · 17–27 months · 5–10 min
- Cardboard Box Circle and Square · 20–30 months · 5–10 min
Top of the ladder (chooses by looking). Keep it flexible: offer it in a new place, with a different person or with new materials.
Activities that fit this step
- Turn-to-Fit Slot Box · 16–30 months · 5–12 min
- One Open Hole Shape Sorter · 17–27 months · 5–10 min
- Cardboard Box Circle and Square · 20–30 months · 5–10 min
The shape sorting ladder
5 steps from the first sign to a flexible skill, covered here from 15 to 36 months. Children move at their own pace: use the steps to see what comes next, not as deadlines.
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Posts through an open top
Drops pieces into the sorter with the lid off, or through the only hole left open.
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Fits the circle
Pushes the round piece through the round hole, which works whichever way it is turned.
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Tries another hole
Presses a piece against the wrong hole, then moves to a different one without help.
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Turns the piece
Rotates a square or triangle in the hand until its corners line up with the hole.
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Chooses by looking
Glances from piece to holes and picks the right one on the first try.
When shape sorting usually shows up
Shape sorters are not on the CDC checklists. Many toddlers post a round piece through a single open hole in the second year; choosing between holes and turning a square or triangle to fit usually comes between about 2 and 3, after plenty of trial and error.
This page follows shape sorting from 15 to 36 months, a window that spans the 15-month, 18-month, 24-month, 30-month and 36-month CDC checklists.
In the library, 3 activities practise shape sorting (3 as their main skill), for ages 16 to 30 months. Each needs a few minutes of setup. By age, they sit closest to steps 2 and 3 of the 5-step ladder, most (2) on “Fits the circle”.
Activities that practise shape sorting
Placed on the closest ladder step by age. By primary domain: 3 fine motor. Quickest to start: Cardboard Box Circle and Square (5–10 minutes).
Step 2: Fits the circle
Step 3: Tries another hole
Skills practised alongside
The activities for shape sorting most often also work on colors and shapes (2), problem solving (2) and posting objects (1). Pairing them keeps practice playful: one activity, several skills.
Practise it inside everyday routines
- Tape over all holes but one, then open one more hole at a time over the weeks.
- Hand over a piece already turned the right way, so your child only has to push.
- Name the shape as it drops ("circle, in!") rather than quizzing your child on shape names.
- Make a sorter from a box lid with one round hole and one slot, and add a third shape later.
What to avoid
- Pushing the piece through after one failed try; a short struggle is exactly where turning gets learned.
When to mention it to the pediatrician
A child who ignores shape sorters is not a cause for worry by itself. If your child seldom explores how objects fit in and out of containers, or has trouble using both hands together by age 2, mention that to the pediatrician.
Worried about shape sorting between visits? Call the pediatrician; CDC's free resources also explain how to contact your local Early Intervention program directly. Milestones are for monitoring, not diagnosis.
Frequently asked questions
When do toddlers start shape sorting?
Shape sorters are not on the CDC checklists. Many toddlers post a round piece through a single open hole in the second year; choosing between holes and turning a square or triangle to fit usually comes between about 2 and 3, after plenty of trial and error. The first step to look for: drops pieces into the sorter with the lid off, or through the only hole left open.
How can I help my toddler with shape sorting?
Tape over all holes but one, then open one more hole at a time over the weeks. Hand over a piece already turned the right way, so your child only has to push. A good first activity is Turn-to-Fit Slot Box (16–30 months).
What should I avoid when practising shape sorting?
Pushing the piece through after one failed try; a short struggle is exactly where turning gets learned.
When should I mention shape sorting to the pediatrician?
A child who ignores shape sorters is not a cause for worry by itself. If your child seldom explores how objects fit in and out of containers, or has trouble using both hands together by age 2, mention that to the pediatrician. You can also contact Early Intervention yourself.
Related
Monitoring, not medical advice. Talk to your pediatrician about any concern. Our sources and method.