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Counting On and Counting Back

A 40-minute Grade 1 lesson connecting the count sequence to arithmetic — adding two means two steps forward, and the off-by-one error has a cause worth naming.

Counting On and Counting Back is a free 40-minute Grade 1 maths lesson plan for Common Core standard 1.OA.C.5 — count on to add, and count back to subtract. 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 1
Length:
40 minutes
Standard:
1.OA.C.5

Grade 1 · Operations & Algebraic Thinking

1.OA.C.5

Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

Objective

Students will be able to add and subtract small amounts by counting on or back from the larger number, without restarting at one.

Students are successful when they can

  • Counts on from the larger addend rather than from one.
  • Says the first count word as the number after the start, not the start itself.
  • Counts back accurately to subtract within 20.

What you need

  • Number lines 0-20, one per pupil
  • Counters to mark positions
  • Number cards 1-20
  • The printable practice sheet linked at the end of this plan

The lesson

Warm-up — jump the line

5 min
  1. Put a counter on 9 on a shared number line. Take three jumps forward together, counting 10, 11, 12.
  2. Then three jumps back. The counting words are what matters here, not the arithmetic.

Teach — where the first jump lands

12 min
  1. Write 9 + 3. Start a finger on 9 and deliberately count '9, 10, 11' while jumping three times. Announce 11 as the answer.
  2. Let the class object. Someone will. Ask what went wrong.
  3. Name it: the 9 was counted as a jump, but you were already there. The first jump lands on 10.
  4. Redo it correctly: 10, 11, 12. Three jumps, three numbers said, and 9 is not one of them.
  5. Do 14 − 4 the same way, counting back 13, 12, 11, 10, and note the same trap in reverse.
  6. Finish with 3 + 9 and ask which number to start from. Starting from 9 is three jumps; starting from 3 is nine.
“Do not say the number you are standing on. Say the one you land on. The first jump is the first new number.”

Guided practice — jump and say

11 min
  1. Pairs use a number line. One says a calculation, the other jumps and says each landing number aloud.
  2. The listener's job is to check the first word is not the starting number.
  3. Include several where the smaller number comes first, so choosing the start becomes a decision.

Independent practice

9 min
  1. Students complete a count-on page with a number line available.
  2. Answers exactly one too high are the off-by-one error and need the first-jump rule, not more practice.

Close

3 min
  1. Ask 7 + 2 and 2 + 7 back to back and ask which was easier.
  2. The answer — start from the bigger one — is the habit worth ending on.

What goes wrong, and why

Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.

Answers 9 + 3 as 11.

Why: The starting number has been counted as the first step. Counting objects has always begun with 'one' on the first object, and that habit is being carried across to counting jumps.

Fix: Physically jump along a number line. You cannot jump onto the square you are already standing on, so the rule becomes obvious in the body before it is stated.

Counts on from the first number given, even when it is much smaller.

Why: The expression is being read left to right, and the left number is assumed to be the starting point.

Fix: Time both routes. Nine jumps versus three jumps for the same answer is an argument the pupil makes to themselves.

Counts back accurately in the twenties but loses the decade: 21, 20, 19, 10.

Why: The decade boundary in reverse is the hardest join in the sequence, and 'ten' is the more familiar word to land on after nineteen.

Fix: Practise the joins alone — 22, 21, 20, 19 — as short bursts. The rest of the count is fluent and does not need the practice.

If they are not there yet

  • Add and subtract 1 and 2 only, where the whole jump can be held in mind and the first-jump rule is the only difficulty.
  • Use a physical number track the pupil can move a counter along rather than a printed line.

If they finish early

  • Count on in twos and fives, where the jumps are bigger than the counting words.
  • Count on from a two-digit number across a decade — 68 + 5.
  • Ask how counting on could be used to solve 15 − 12 more easily than counting back.

Exit ticket

Work out 8 + 3 by counting on. Write the numbers you said.

What to look for: 9, 10, 11 and the answer 11. A pupil who wrote 8, 9, 10 and answered 10 has the off-by-one error — a number line and the first-jump rule tomorrow, not more sums.

Printable practice for 1.OA.C.5

Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.

Questions about Counting On and Counting Back

How long does the Counting On and Counting Back lesson take?

40 minutes, split across 5 timed sections: warm-up 5 min, teach 12 min, guided practice 11 min, independent practice 9 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 Counting On and Counting Back teach?

CCSS.MATH.CONTENT.1.OA.C.5 — 1.OA.C.5, Operations & Algebraic Thinking for Grade 1: “Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).” In plain terms, count on to add, and count back to subtract.

What do I need to teach this lesson?

Number lines 0-20, one per pupil, counters to mark positions, number cards 1-20 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: answers 9 + 3 as 11; counts on from the first number given, even when it is much smaller and counts back accurately in the twenties but loses the decade: 21, 20, 19, 10. 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: “Work out 8 + 3 by counting on. Write the numbers you said.” 9, 10, 11 and the answer 11. A pupil who wrote 8, 9, 10 and answered 10 has the off-by-one error — a number line and the first-jump rule tomorrow, not more sums. 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 Counting On and Counting Back?

Yes — 2 printable 1.OA.C.5 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 Counting On and Counting Back 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 1.OA.C.5 of the Common Core State Standards for mathematics.