Snowball

Two children agree an answer. Then two pairs merge and agree again. Then two fours. By the last round eight children are defending one sentence — and deciding what to throw away is the actual thinking.

Cutting is the skill. Every round has to lose something, which is what makes it harder than ordinary group work.

Nothing to set up. A question with more good answers than you want to end up with.

Ten minutes. Three rounds, each one shorter on ideas and longer on argument.

A timer for each stage, with what the children do in each · free to try · no sign-up

The sheet it prints — optional

The printable Snowball sheet — an A4 page with shrinking space for each round, from five lines alone to two lines in a group of eight.

What is the snowball activity?

Snowball is a cooperative learning structure in which children agree an answer in pairs, then merge with another pair to agree again as a four, then merge again as an eight — so the surviving answer has been argued over three times by progressively larger groups. It is sometimes called snowballing or pyramid discussion.

The name describes the group size, not the amount of content. The ideas do the opposite of snowballing: they get fewer and sharper at every stage, because each merge forces a choice about what to leave behind.

How do you run a snowball activity, step by step?

Pairs (about two minutes). Two children agree one answer between them. Not two answers written next to each other — one.
Fours (about three minutes). Each pair joins another pair, compares, and agrees a single answer for the four. Say out loud that they are allowed to abandon their own.
Eights (about three minutes). Two fours merge and must come back with one answer between eight people.

Ten minutes end to end. If your class does not divide into eights, stop at fours — three rounds is not sacred and a lopsided last merge is worse than a short one.

What makes a good snowball question?

One with more defensible answers than you want to finish with. “What is the most important cause of the Great Fire spreading?” works because there are five candidates and only one can win. “What year was the Great Fire?” collapses at the first merge.

The test is whether a group could reasonably have to give something up. If nothing has to be dropped, you have run a very slow version of asking the class a question.

From the classroom

The mistake I made for a long time was letting groups write a longer answer at each round. It felt like progress and it was the opposite — by the eights stage they had a paragraph that was just all four pair answers stapled together, and nobody had decided anything. Now I give them fewer lines to write on at every merge, physically: five lines in the pair, four in the four, two in the eight. The constraint does the teaching. The other thing worth knowing is that the eights stage is where it gets loud and where the learning is, so do not cut it to save time — cut the pairs stage instead. With Year 3 I stop at fours entirely; eight seven-year-olds negotiating one sentence is a lovely idea and I have never once seen it work.

What usually goes wrong with snowballing?

Answers get longer instead of shorter. The groups combine rather than choose. Shrinking the writing space at each round fixes it faster than any instruction.
The merges are uneven. A four joining a two makes the bigger group win by weight of numbers. Sort the group sizes before you start, not during.
The last round runs out of time, which is the one that matters most. Protect it.
Nobody wants to give up their own answer. Say explicitly at the start that abandoning your answer is a win, not a loss.

Which year groups is snowball for?

Year group	US grade	What to change	How long
Years 2–3	Grades 1–2	Two rounds only, pairs to fours. Answers of a few words.	6 min
Years 4–5	Grades 3–4	Three rounds. Shrink the writing space each time.	10 min
Year 6 and up	Grades 5–8	Ask the eight to report what they dropped and why — that is the richer answer.	12 min

Snowball compared with the other consensus structures

Placemat keeps every individual answer visible on the page and negotiates one middle. Snowball deliberately loses the individual answers along the way.
Think Pair Share is one merge instead of three — five minutes rather than ten, and no cutting.
Diamond Nine also forces ranking and dropping, but against a fixed set of cards rather than the children’s own ideas.

Free to try · no sign-up · the sheet is optional

Placemat →The other consensus structure — but it keeps every individual answer on the page instead of merging them away. All 24 cooperative structures →Think Pair Share, Round Robin, Four Corners and the rest — each with a timer and a step-by-step.

Written by a practising primary school teacher, and part of the free-to-try Teaching Routines set on Sage Teachers. Last checked August 2026. Everything here is free to try.