Sorting objects into groups

When you reach for it

Sorting means putting a mixed pile into groups by one rule, such as color, size, kind, or what a thing is used for. A good rule gives every object exactly one group, so anyone can check where each one goes. Once the pile is sorted, each group is counted, which turns a jumble into a few clear numbers. Reach for it once a child can count a small group and say how many.

Each day below takes ten to fifteen minutes. Keep every group at ten or fewer, and always say the rule out loud before anything is sorted.

Day 1: Sorting by a rule you are given

You need: about ten buttons or counters in two colors, and two bowls.

Mix the counters on the table. Point to one bowl and say, “Dark ones go here.” Point to the other: “White ones go here.” Let the child pick up one counter at a time, say its color, and drop it in its bowl. When the table is empty, ask, “Is anything left on the table? Is each counter in its own bowl?”

Now count. Pour out one bowl, count it, and ask, “How many dark counters?” Then the other bowl. Each answer is the last counting word said for that group.

Practice.

1. Sort the counters in the picture by color. How many in each group? Answer: 5 dark and 4 white.
2. Mix 6 yellow cubes and 2 green cubes and hand them over. Sort by color and count each bowl. Answer: 6 yellow and 2 green, and no cube is left on the table.
3. Mix 3 spoons and 6 forks. Sort them by what they are. Answer: 3 spoons and 6 forks.
4. Mix 3 socks, 2 mittens and 4 hats, with three spots on the floor. Sort them by kind. Answer: 3 socks, 2 mittens and 4 hats. A rule can make three groups as easily as two.

Day 2: Checking a sort

You need: two bowls or trays, counters in two colors, and a few small things from around the room (crayons, a spoon, a fork, a marker, a toy car).

Sort a handful of counters by color yourself, but drop one into the wrong bowl on purpose. Ask, “Is every counter in the right bowl? How do you know?” Checking means looking at each object against the rule, one at a time. When the child finds the stray one and moves it, count both groups again, since the numbers have changed.

Then sort by what things are used for: “things to draw with” in one tray, “things to eat with” in the other. Slip in the toy car. It fits neither tray, so it is set aside, and that is fine. A rule says where each thing goes, and a thing the rule does not cover stays out of the count.

Practice.

1. In the picture, which counter is in the wrong tray? Answer: the white counter in tray A.
2. Move it to its right tray, then count each tray. Answer: tray A has 4 dark counters and tray B has 4 white counters.
3. Sort 3 crayons, 2 markers, 2 forks and 1 spoon into “to draw with” and “to eat with”. How many in each? Answer: 5 things to draw with (3 crayons and 2 markers) and 3 to eat with (2 forks and 1 spoon).
4. A toy car is in the “to eat with” tray. Where does it belong? Answer: in neither tray. It is not used for drawing or eating, so it is set aside.

Day 3: The same pile, sorted a second way

You need: about eight buttons or counters in two colors and two sizes, and two bowls.

Sort the pile by color and count each bowl. Then pour everything back together and ask, “Can we sort these a different way?” If the child does not see one, hold up a big one and a small one. Sort by size and count again. The groups are different, but nothing was added or taken away, so the whole pile is the same both times. Count the whole pile once to see it.

Practice.

1. Sort the counters in the picture by color. How many in each group? Answer: 5 dark and 3 white.
2. Sort the same counters by size. How many in each group? Answer: 4 big and 4 small.
3. How many counters are in the whole pile? Answer: 8. Both sorts used every one of the 8, since 5 and 3 make 8, and so do 4 and 4.
4. A pile has 3 big red buttons, 1 small red button and 2 small blue buttons. Sort it by color, then by size. Answer: by color, 4 red and 2 blue; by size, 3 big and 3 small.

Day 4: Choosing the rule

You need: a mix of about ten round buttons and square blocks in two colors, and bowls.

Hand the child the mixed pile and ask, “How could you sort these? Tell me your rule first.” Any rule that gives every piece one group is a good rule. After the sort, the child counts each group and says the rule again: “These are round, and there are five.”

Then play “guess my rule.” Sort a few things yourself without saying how, and ask the child what rule you used. To test a guess, hand over one more thing: “Where does this go?”

Practice.

1. Sort the pieces in the picture by kind, buttons and blocks. Answer: 5 round buttons and 5 square blocks.
2. Sort the same pieces by color. Answer: 6 dark and 4 white.
3. Guess my rule: a cup, a plate and a spoon in one group, a pencil and a crayon in the other. Answer: things for eating and things for drawing; the groups have 3 and 2.
4. The child sorts some shoes by “has laces” and “no laces”. Is that a good rule? Answer: yes. Every shoe either has laces or does not, so each shoe gets exactly one group.

Exercises

1. Sort the counters in the check picture by color. How many are in each group?
2. Pour them back and sort the same counters by size. How many are in each group, and how many counters are there in all?

Where this goes next

Once a pile is sorted and each group counted, the next step is to put the groups in order by how many. Sorting by color, size or kind is also how a child notices the parts of a repeating pattern. Sorting flat shapes by their sides and corners is the work of Sides, corners and sorting shapes. Later, each sorted group becomes one row of a tally table and one bar or row of pictures in a graph.