Number Bonds to 20 Sort Task Box

About this resource

EVERYTHING INSIDE — 22 pages

• 12 number bond cards across 3 levels, each card showing the whole (20, given) and ONE part as a dot group — the child marks the choice tile naming the MISSING part
• Every card twice: accent-filled dots for a laminated classroom box and black-filled ink-saver dots for the photocopier
• A number bond reference strip (color and ink-saver): every way to split 20 into two parts, 1 and 19 through 19 and 1, each shown as two dot groups side by side
• An answer key listing every card by level, written out as "part + ? = 20" with the missing part and every choice on the card
• A task box data sheet (16 rows: date, level, cards used, cards correct, cards given, percent, help given, initials)
• A percent graph, 14 sessions across, with a level box under each session
• A filled example — an invented student, 8 sessions, every percent re-counted from its own row
• A family practice page with six of the same cards and the same "how many more to make twenty" prompt
• A phrase bank: spoken lines for running the box and written starters for the note afterward, in 6 groups
• Start Here, a contents page with page thumbnails, and a "what's next" back page

A task box built around the part-part-whole shape of a number bond, not a two-dot-groups-plus-sum addition fact — this asks "what's the missing part of twenty," and it sits beside the collection's Number Bonds to 10 set as the next step up once a student is solid at the smaller whole, without repeating that box's cards.

Three Levels, Each Testing Something Different

• Level 1 — known part at the extremes of the range (1-2 or 18-19). The dot group is very small or very large, the missing part is easy to picture, and the wrong choice is always at least 4 away from it — nearly impossible to get wrong.
• Level 2 — known part moving toward the middle (7-8 or 12-13), three choices, wrong choices never adjacent to the missing part, and the missing part's own tile position varies card to card.
• Level 3 — known part at or beside half of twenty (9, 10 or 11) — the hardest split to eyeball, because both parts of the bond end up nearly or exactly the same size. At least one wrong choice sits exactly one away from the true missing part, the near-miss a child lands on after missing or double-counting a single dot.

Nothing on a card says its level except a dot code in the corner (one, two or three dots), so a mixed-up box sorts itself back together.

NO PICTURES, ON PURPOSE — every dot is a plain filled circle and every numeral a plain printed tile, drawn the same way in both the color set and the ink-saver set. There is no picture library to run out of and no image to misread; the only thing a child reads is dots and numerals.

What This Is, And What It Is Not

It is a fillable PDF: type into the data sheet, the graph header, the family page and the example-style notes, or print and use a pen. The card pages and reference strip print on cardstock or plain paper and cut along dashed lines. It works offline with no account or subscription. It is NOT an editable online slideshow or word-processor document, and it is not a test of anything.

It carries no prompt hierarchy, fading schedule or mastery rule, and it does not decide what a percent means for a student or when to move up a level. The goal line and the criterion field are blanks for your district's own wording and your team's own number. It measures one thing: cards with the right missing part marked.

Who This Is For

Special education teachers and paraprofessionals running independent work stations or task box rotations with students working on number bonds to 20, case managers who need that practice to show up as data, and the families who get the practice page sent home.

More In The Collection

This is one set in the Task Box Collection; more sort, counting and number-sense boxes are being added to the collection regularly, all on the same cards-plus-data shape.