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Day 2 — Twenty plus ones: 21–24Year 1 Maths · T1 W1–2 · Day 2 lesson

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Year 1 / Mathematics / Term 1 / Weeks 01 02

Part of the full two-week lesson sequence. Check the pack guide and taught point before teaching.

Open for this lesson: Pack guide.

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Teacher copy: This page may include teaching prompts or answer keys. Answer keys in this public library can be viewed by anyone. Give learners a clean prompt, use checks as formative evidence, and change a case locally when prior access matters.

Goal: see a two-digit number as known tens and ones. Materials: two ten-strips and four ones per learner, mat, library card.

  1. Notice, 3: Build 20 from yesterday. Ask “What changes if I add one loose book picture?” Key: 21, not another ten.
  2. Model, 5: Place 2 strips in TENS, 3 objects in ONES. “Two tens are twenty. Three ones are three. Twenty-three is 20+3. The 2 tells me tens, the 3 tells me ones.” Write 23 after building.
  3. Together, 8: Build 21, 22, 23, 24 one at a time. For each, point to 20 then count on the loose ones, locate the numeral on the track, and swap models with a partner. Use the library card for 23.
  4. Try, 6: Give a mixed mat of 2 strips and 4 ones. Learner labels 24, then removes one and relabels 23. Offer digit cards 2 and 4 for selection rather than pencil control.
  5. Check, 3: Display 2 tens and 1 one. “Show the numeral; tell me 20+__.” Key: 21 and 1. If 12 appears, point to column labels, rebuild 1 ten + 2 ones as 12 and contrast both.

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