Useful outcome: Organise, audit and skip count a real represented collection through 120, with honest evidence of the range actually completed.
Prepare: Ordinary large-collection aid with 120 actual unlabelled marks; keep its teacher total out of the own prompt. Smaller child-chosen quantities and large/directed marking are available. Prepare a sixty-mark guided set and a 120 count trail.
Notice · 3 minutes
Ask how a pretend display-maker could avoid recounting a large picture collection. Children can choose groups or a counted/not-counted division. A prediction is retained as a prediction until grouping/counting is actually performed.
Model · 5 minutes
Use a different fifty-mark set: make five audited tens and count 10,20,30,40,50; or ten fives. Show how to audit one group and full coverage. Do not label the own large collection’s total or pre-sort it into twelve tens.
Guided attempt · 8 minutes
Compare sixty as six tens/twelve fives. Then link successive ten-steps 10 through 120 to actual complete units on the count trail. The linked trail is a supported example, not proof of independent partitioning of the unlabelled large field.
Own choice · 6 minutes
Choose one route; the child selects/directs the mathematical action. A different route is available later.
Route A · Display-maker
Child task: Choose and make a grouping for the unlabelled 120-mark field; count it and check full coverage.
Teacher move: Ask which marks remain unassigned; an adult draws only boundaries directed by the child.
Observe: Actual chosen units, no omissions/reuse, cumulative count and 120 only if genuinely completed.
Next move: If unfinished, retain partial range and continue later; if membership fails, teach the same goal on a new smaller set.
Route B · Long count trail
Child task: Make successive full tens and a linked 10-through 120 sequence; change orientation and check it.
Teacher move: Ask what one step counts and what the last step includes.
Observe: Twelve actual tens and their cumulative labels; orientation does not change quantities.
Next move: If only labels are copied, reconnect one full group per step and collect a new count attempt.
Route C · Two accounts, own set
Child task: Count sixty as fives/tens; then choose and verify an own manageable larger collection, at most 120 in this offer.
Teacher move: Record the actual selected size and support; ask for one unit audit and coverage check.
Observe: Child’s actual selected range, strategy and total; no unmade 120 claim.
Next move: Choose next range from evidence; a smaller accurate account is useful partial work, then a new larger opportunity.
Exit and same-day next teaching · 3 minutes
Give three full tens and ask what the count 30 includes. Then ask how a new fourth ten changes it.
Teaching reference: All 30 objects in the first three groups; the fourth adds 10 for 40.
Choose next: Continue at the range/strategy actually shown. A completed teacher count, a prediction or uncompleted diagram is not pupil quantification through 120.
Retain the first response, actual range and support; a later corrected or adult-supplied model is a separate record.