Odd and Even Numbers
A 45-minute Grade 2 lesson defining even as 'pairs up with none left over' rather than as a list of digits to memorise, so the rule can be tested on any number.
Odd and Even Numbers is a free 45-minute Grade 2 maths lesson plan for Common Core standard 2.OA.C.3 — tell whether a number is odd or even. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 2
- Length:
- 45 minutes
- Standard:
- 2.OA.C.3
Grade 2 · Operations & Algebraic Thinking
2.OA.C.3
Determine whether a group of objects (up to 20) has an odd or even number of members.
Objective
Students will be able to decide whether a number is odd or even by pairing, and explain why the last digit is enough to tell.
Students are successful when they can
- Pairs up objects and reports whether one is left over.
- Classifies numbers to 100 as odd or even.
- Explains why only the last digit matters.
What you need
- Counters, 30 per pair
- Ten frames
- A hundred square to shade
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — pair them up
5 min- Give each pair a handful of counters and ask them to make pairs.
- Report back: leftover or not. Do not name odd and even yet.
Teach — the leftover decides it
13 min- Line 8 counters into 4 pairs. Nothing left over. Name it: even.
- Line 9 counters into 4 pairs with one alone. Name it: odd.
- Do 12, 15 and 20 the same way, recording each result.
- Now shade the even numbers on a hundred square. The columns are the point — every even number ends in 0, 2, 4, 6 or 8.
- Ask why. Pair up the tens first: every ten pairs up perfectly, so the tens never leave anything over. Only the ones can.
- Test it on 46 without counting 46 counters. Four tens pair up; six pairs up; even.
“Even does not mean it ends in a 4. It means everything pairs up. The last digit is a shortcut that works because tens always pair.”
Guided practice — predict then check
12 min- Pairs predict odd or even for a number card, then check by pairing counters for small numbers.
- For numbers over 20 they must justify by the tens argument rather than by counting out.
- Include 0, which pairs up trivially and is even. Let the argument happen.
Independent practice
12 min- Students complete an odd or even page.
- Errors on numbers ending in 0 are common — zero left over is still nothing left over.
Close
3 min- Ask whether 37 is odd or even and how they know without counting.
- 'Seven does not pair up' is the answer to end on.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Says 30 is odd.
Why: Zero is being read as nothing to pair, and nothing feels like it cannot pair. The digit 0 has not been included in the memorised list either.
Fix: Pair up 10 counters, then 20, then 30. Every ten pairs completely, so a number of whole tens always pairs. Zero left over is the definition of even.
Decides odd or even by whether the whole number 'looks big or small'.
Why: No rule has been internalised, so a guess is being made on the only property available.
Fix: Go back to pairing physical counters for a week. The definition has to be built before the digit shortcut can mean anything.
Memorises the digit list and cannot apply it to a three-digit number.
Why: The rule was learned as a fact about two-digit numbers rather than as a consequence of tens pairing up.
Fix: Ask why the rule works. A pupil who can say 'the tens always pair' applies it to 348 without being told it extends.
If they are not there yet
- Work within 20 with physical counters only, and add the digit shortcut once pairing is automatic.
- Use ten frames, where an even number fills complete rows of two and the leftover is visible.
If they finish early
- Add two even numbers and predict whether the result is odd or even, then test it.
- Work out whether an odd number plus an odd number is odd, and explain why with counters.
- Write an even number as a sum of two equal addends.
Exit ticket
Is 26 odd or even? Is 40? Explain how you know for 40.
What to look for: Even and even, with an explanation about zero pairing or four tens pairing. 'Odd' for 40 means zero is still being read as unpairable.
Printable practice for 2.OA.C.3
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Odd or Even to 20Write odd or even for each.
- Odd or Even to 50Write odd or even for each.
Questions about Odd and Even Numbers
How long does the Odd and Even Numbers lesson take?
45 minutes, split across 5 timed sections: warm-up 5 min, teach 13 min, guided practice 12 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Odd and Even Numbers teach?
CCSS.MATH.CONTENT.2.OA.C.3 — 2.OA.C.3, Operations & Algebraic Thinking for Grade 2: “Determine whether a group of objects (up to 20) has an odd or even number of members.” In plain terms, tell whether a number is odd or even.
What do I need to teach this lesson?
Counters, 30 per pair, ten frames, a hundred square to shade and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: says 30 is odd; decides odd or even by whether the whole number 'looks big or small' and memorises the digit list and cannot apply it to a three-digit number. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Is 26 odd or even? Is 40? Explain how you know for 40.” Even and even, with an explanation about zero pairing or four tens pairing. 'Odd' for 40 means zero is still being read as unpairable. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Odd and Even Numbers?
Yes — 2 printable 2.OA.C.3 worksheets, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Odd and Even Numbers free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 5 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-05. Aligned to 2.OA.C.3 of the Common Core State Standards for mathematics.