Sorting by What You Can See
A 50-minute Grade 2 lesson on describing and classifying materials by the properties you can observe.
Sorting by What You Can See is a free 50-minute Grade 2 science lesson plan for Common Core standard 2-PS1-1 — sort materials by what you can observe about them. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 2
- Length:
- 50 minutes
- Standard:
- 2-PS1-1
Grade 2 · Physical Science
2-PS1-1
Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.
Objective
Students will be able to describe a material by its properties and sort it into a group.
Students are successful when they can
- Describes a material using observable properties.
- Sorts materials into groups by a stated property.
- Says which property was used to sort.
What you need
- A tray of six materials: wool, steel, glass, rubber, card, plastic
- Hoops or labelled trays for sorting
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — describe it without naming it
5 min- Hold a material behind your back and describe it by its properties.
- Let the class guess, then ask which words helped most.
Teach — properties, then groups
13 min- Build a class list of property words: hard, soft, bendy, stiff, shiny, see-through.
- Describe steel with three of them, then wool with three.
- Sort the six materials by hard and soft, and say which property was used.
- Re-sort the SAME six by see-through and not, and show that the groups change.
- Say the point: the groups depend on which property you sort by.
- Refuse a non-property: 'nice' cannot be observed and does not sort anything.
“Which property are we sorting by this time?”
Investigate — sort three ways
17 min- Groups take a tray of materials and sort them by hard and soft.
- They record the groups, then re-sort by bendy and stiff.
- They re-sort a third time by see-through and not.
- They notice which materials moved between sorts and which did not.
Independent practice
12 min- Students complete the 'Sorting by What You Can See' page.
- Check the sorting words are observable properties.
Close
3 min- Hold up a new material and ask which group it joins, and why.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Sorts by what the object is used for.
Why: Use is the familiar way to group things.
Fix: That is the next lesson. This one sorts by what you can observe.
Uses opinion words like 'nice' as properties.
Why: They are true of how it feels to them.
Fix: Ask whether everybody would agree. A property is something anybody can check.
Thinks a material belongs to only one group.
Why: One sort produced one answer.
Fix: Re-sort by a different property. Plastic is hard AND can be see-through.
If they are not there yet
- Four materials and one sorting property.
- Property words on cards to place beside each material.
If they finish early
- Find a property that splits the tray exactly in half.
- Find two materials that share every property on your list.
- Add a material that would not fit any of your groups.
Exit ticket
Describe steel using two properties, and say which group it goes in.
What to look for: Two observable properties such as hard and shiny, with the group named. 'Useful' or 'good' means the property idea needs another run.
Printable practice for 2-PS1-1
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Sorting by What You Can SeeSort each material into the right group.
Questions about Sorting by What You Can See
How long does the Sorting by What You Can See lesson take?
50 minutes, split across 5 timed sections: warm-up 5 min, teach 13 min, investigate 17 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Sorting by What You Can See teach?
2-PS1-1 — 2-PS1-1, Physical Science for Grade 2: “Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.” In plain terms, sort materials by what you can observe about them.
What do I need to teach this lesson?
A tray of six materials: wool, steel, glass, rubber, card, plastic, hoops or labelled trays for sorting and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: sorts by what the object is used for; uses opinion words like 'nice' as properties and thinks a material belongs to only one group. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Describe steel using two properties, and say which group it goes in.” Two observable properties such as hard and shiny, with the group named. 'Useful' or 'good' means the property idea needs another run. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Sorting by What You Can See?
Yes — 1 printable 2-PS1-1 worksheet, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Sorting by What You Can See free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 8 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-08. Aligned to 2-PS1-1 of the Next Generation Science Standards.