BRIJBOX · A PART WITH NOTHING IN IT · CHILD SHEET

This part is holding zero.

Five counters, some in each part. Then move them all into one part — and look carefully at the other one. Its line is still here, so the part is still here. It is holding zero.

The ★ marks the part we are talking about. Both lines stay just as strong when a part is empty.

Our bond

The whole on top, each part below it. Point from every circle to the group it stands for — including the empty one.

BRIJBOX · A PART WITH NOTHING IN IT · THE BASKETS

Make one basket empty.

Eight pegs and two baskets. Count the eight first. Then ask your child to put the pegs in the baskets so that one basket is empty — this time they make the empty part themselves.

Draw what you made

Then: “How many in this basket?” (the empty one) … “How many in that basket?” … “How many in the whole?” The whole gesture must include the empty basket.

BRIJBOX · A PART WITH NOTHING IN IT · GROWN-UP GUIDE

Is it still a part?

Exactly five counters, two group areas inside one boundary, a blank bond and numeral cards 0–9; then exactly eight pegs and two baskets. App 2–3 min → table 12–15 min → app practice 2–3 min. The table is the longest part, and these are estimates, not deadlines. These sheets are the complete no-device fallback.

1. Start in known territory. Five counters split 2-and-3: “Show me the whole.” … “Show me the parts.” Then “Move all the blocks into this part” — the child moves every counter into one area, in their own view.
2. Name the empty part. Point at the empty area: “Look at this part. How many blocks are in it?” Wait. Zero, “none” and “nothing” are all correct; then you attach the number: “Yes — zero. This part has zero blocks.” Then “Is it still a part?” — if they hesitate, trace the still-visible boundary. Then “Show me the whole. How many?” The sweep must include the empty area; the whole is still five.
3. Bond it. “What number goes with the whole?” (5) “How many in this part?” (5) “And this part?” (0) The child places or dictates each number; point every circle back to its actual group. Read it together: “Five and zero make five.”
4. Explain. Rebuild a non-empty split of the child’s choice, then move all five back to one side again. “What changed?” … wait … “What stayed the same?” Recount the five across both areas, including the empty one.
5. Transfer: eight pegs and two baskets. “How many pegs?” (8) Then “Put the pegs in the baskets so that one basket is empty.” — the child now produces the empty part themselves. “How many in this basket?” (point to the empty one) … “How many in that basket?” … “How many in the whole?”
6. Sitting boundary: a coherent stop is after step 3; steps 4–5 take a flexible sitting, re-entering with “Show me a part with zero.”

Task-change language only: “In our last lesson we chose some for each group. Today we are trying the empty way — it is allowed.” Zero is never framed as an error or a broken rule. Keep every spare object away — the empty group must be genuinely empty, not “empty except the reserves beside it” — and keep its boundary visible at all times. A swap (0-and-5 against 5-and-0) is the same pair: an observation, never a correction.

What did you notice?

Practice on screen is rehearsal of naming an empty group and of putting zero in a bond. It supports, but cannot itself supply, the table-observed rows below. Your paper card remains the evidence record.

• Names the empty group as a part with zero: points and names it unprompted. After you trace the boundary, or supply the word “zero”, record supported. Accept “none” plus pointing — word-finding can mask the idea.
• Records 5, 5 and 0 against the actual groups: places or dictates all three. Needing the circles re-mapped to groups is supported; use numeral cards if writing is the obstacle.
• The whole stays five through the all-in-one move: recounts or cites the complete set. Your routine “how many?” is ordinary task delivery, not support.
• Transfer: builds the empty part with eight pegs, names 0 and 8, and sweeps both baskets. Excluding the empty basket from the whole, or reusing five, does not pass.

Mark each row independent / supported / revisit / uncertain. Leave anything you did not observe uncertain. Nothing is scored or stored.

Trial notes — leave blank until observed