Year 2 Maths · Term 2 · Weeks 13–14

Spot-the-value-error cards

Make a small check-and-repair card set. Find what a supplied card gets wrong, make a replacement and explain why the place values support it.

15–30 adjustable minutes or several short offers; optional project, not required homework.

Whole launch source: supplied draft claims

Fictional draft cards for a pretend train-label guide. The known quantities are first 309 labels, second 390 labels and third 903 labels, all counting the same kind of label, not prices or observed stock. One hundred has the value of ten tens; one ten has the value of ten ones. The three draft cards below contain claims to check; they are supplied mistakes, not worked answers. Draft card 1 prints 309 and shows 3 hundreds, 9 tens and 0 ones. Draft card 2 calls the order 903, 390, 309 “least to greatest”. Draft card 3 says 309 and 903 have equal value because they use the same digits.

Choose a draft card. Show or tell how you can check it using the whole values. Keep the draft, then make a replacement card and give your reason. Label any zero place. You can check more cards when you are ready.

Check and make your replacement

  1. Read or hear the whole source and choose one draft card to check. The supplied claims are not your answers.
  2. Keep your first check before opening the adult model. Use place-value cards, marks, speech, sign/AAC, pointing or exact adult scribing.
  3. Show the value of the supplied groups or compare the full quantities. If a claim is wrong, make a replacement card; if you later meet a correct claim, explain why you keep it.
  4. Keep the supplied draft and your replacement separately, with your own checking reason. A fictional reader or solo rehearsal is fine.
  5. If a willing reader tries your card, record only what they actually do or say, with permission. Otherwise leave the reader test proposed. Recheck after any change.
Adult possibility after the own try

One possible adult check after the own try: draft card 1 is wrong because its groups are 300 + 90 + 0 = 390, not 309. A replacement for 309 can show 3 hundreds, 0 tens and 9 ones: 300 + 0 + 9 = 309. Draft card 2 is wrong: least to greatest is 309, 390, 903. The first two have 3 hundreds, then 0 tens is less than 9 tens; 903 has 9 hundreds. Draft card 3 is wrong: the digits are in different places. 309 is 300 + 0 + 9; 903 is 900 + 0 + 3. Other complete groupings with the same whole value are valid: 30 tens and 9 ones also make 309. Assess the value and the explanation, not a single preferred drawing.

A different guided set: check before keeping or repairing

A different fictional draft set for a pretend label guide. The known quantities are first 508 labels, second 580 labels and third 805 labels, all counting the same kind of label, not prices or observed stock. One hundred has the value of ten tens; one ten has the value of ten ones. Check each supplied claim before deciding whether to keep or repair it; this set includes a correct card. Guided card 1 prints 805 and shows 8 hundreds, 0 tens and 5 ones. Guided card 2 prints 508 and shows 5 hundreds, 8 tens and 0 ones. Guided card 3 says 580 is the greatest of the three quantities.

Use a fresh record for this different set. Choose a card and check its whole value or comparison. Decide whether to keep or repair it, then show or tell your reason before opening the separate guided adult possibility.

Separate adult possibility after the guided own response

One possible adult check after a fresh guided response: guided card 1 is correct: 800 + 0 + 5 = 805, so keep it. Guided card 2 is wrong: its groups are 500 + 80 + 0 = 580, not 508. A replacement for 508 can show 5 hundreds, 0 tens and 8 ones: 500 + 0 + 8 = 508. Fifty tens and 8 ones also make 508; nonstandard regrouping is valid when the whole value is preserved. Guided card 3 is wrong: 805 is greatest because it has 8 hundreds, while 508 and 580 have 5 hundreds. Least to greatest is 508, 580, 805; compare the tens when the hundreds match. Receive the learner’s explanation and record any mathematical help given.

Make it yours

  1. Start with one supplied card, then check another if useful. Use marks, speech, sign/AAC, pointing, tactile place-value cards or exact scribing; handwriting and digital art are not criteria.
  2. Make a large clear replacement card or a quiet one-card version. Preserve the whole values and zero places; several equivalent groupings can be correct.
  3. After checking these drafts, optionally make a new clearly labelled fictional draft for someone to check. State and review its complete source first; do not assume a new claim is wrong merely because its grouping looks unusual.

Look for a check against the complete supplied quantities, a justified decision to keep or repair a claim, and a replacement that preserves its stated whole value. Keep the first and later records and any help given. A finished card, attractive drawing or willing reader does not by itself prove mathematical understanding.