20-minute lesson
Year 1 Mathematics: Counting to 20
Lesson objective
- Say the counting numbers forwards from 1 to 20 and backwards from 10.
- Count a small collection by touching or moving each object once.
- Understand that the last number counted tells how many are in the group.
Success criteria:
- I can count out loud from 1 to 20.
- I can touch each object once as I count it.
- I can tell you how many are in a group after I count it.
- I can say which number comes next.
Materials
- A handful of dry pasta pieces (about 20)
- An empty egg carton or muffin tin
- Small toys, buttons or blocks
- A plastic cup
Introduction
2 minIntroduce today's words:
- count: Saying the numbers in order, one for each object.
- how many: The total number of things in a group.
- more: The group that has the bigger number of things.
- fewer: The group that has the smaller number of things.
- next: The number that comes straight after.
Ask your child what they already know about counting to 20.
Explanation
4 minCounting has two parts. First, children need to know the number names in the right order: one, two, three and so on. Second, they need to match one number to one object, so every object is counted once and only once.
Start by counting out loud together while doing an action, such as clapping or jumping. Once your child can say the numbers to 10 smoothly, keep going to 20. The 'teen' numbers can be tricky because 'eleven' and 'twelve' do not sound like 'one' and 'two'.
To count objects, line them up and move each one into a cup or across the table as you say its number. Moving objects makes it much easier to keep track than just pointing.
The last number you say tells how many are in the group. After counting, ask 'So how many pasta pieces are there?' If your child starts counting again, gently show them that the answer is the last number they said.
Counting backwards is just as important. Try a rocket countdown from 10 to 0 before 'blast off', crouching down low and jumping up at the end.
- Count forwards: 1, 2, 3, 4, 5 …
- Count backwards: 10, 9, 8, 7, 6 …
- The last number said tells how many.
Worked examples
3 minCounting pasta into a cup
There is a small pile of pasta on the table. How many pieces are there?
Step 1: Line the pasta up in a row so none are hiding.
Step 2: Pick up one piece, say 'one' and drop it into the cup.
Step 3: Keep going: 'two', 'three', 'four', 'five', 'six', 'seven', moving one piece each time.
Step 4: When the table is empty, the last number said was 'seven'.
Answer: There are 7 pieces of pasta.
What comes next?
We are counting: 11, 12, 13 … What number comes next?
Step 1: Say the numbers out loud from 10: ten, eleven, twelve, thirteen.
Step 2: Think of the next number: after three comes four, so after thirteen comes fourteen.
Answer: 14 (fourteen) comes next.
Guided practice (do together)
4 min1. What number comes straight after 8?
2. Which number comes just before 5?
(a) 6 (b) 4 (c) 3 (d) 7
3. Count the stars: ★ ★ ★ ★ ★ ★. How many stars are there?
(a) 5 (b) 6 (c) 7 (d) 8
4. Count backwards and fill the gap: 5, 4, 3, ___
Independent practice
5 min5. Lily has 3 apples. Jack has 7 apples. Who has more apples?
(a) Jack, with 7 apples (b) Lily, with 3 apples
6. Which of these is the number twelve?
(a) 21 (b) 10 (c) 12 (d) 20
7. What number comes straight after 15?
8. Fill the gap: 10, 11, 12, ___
(a) 14 (b) 11 (c) 20 (d) 13
Questions to check understanding
- Can you count out loud from 1 to 20?
- Can you touch each object once as I count it?
- Can you tell you how many are in a group after I count it?
- Can you say which number comes next?
- What was the trickiest part today?
Answer guide
1. 9 — Counting on from 8: eight, nine. So 9 comes next.
2. 4 — Counting 1, 2, 3, 4, 5 — the number just before 5 is 4.
3. 6 — Touch each star once: 1, 2, 3, 4, 5, 6. There are 6 stars.
4. 2 — Counting backwards, the number after 3 is 2.
5. Jack, with 7 apples — 7 comes after 3 when we count, so 7 is more than 3. Jack has more.
6. 12 — Twelve is written with a 1 and then a 2: 12. The number 21 is twenty-one.
7. 16 — Fifteen, sixteen. So 16 comes next.
8. 13 — After twelve comes thirteen, so the missing number is 13.
Review
2 minRecap the success criteria together. Watch for these common misconceptions:
- Counting an object twice or skipping one. Encourage moving each object to a new spot as it is counted.
- Thinking the answer to 'how many?' means counting all over again. Show that the last number said is the total.
- Mixing up teen numbers with 'ty' numbers (such as fourteen and forty). Say them slowly and stress the endings.
Extension activities
- Play 'Egg carton count': drop one piece of pasta into each cup of an egg carton and count how many cups are filled.
- Go on a counting walk and count letterboxes, trees or parked cars up to 20.
- Roll a dice and jump that many times, counting each jump out loud.
Suggested follow-up
- Revisit counting to 20 tomorrow with two or three quick questions from memory.
- Try the online practice check for this topic and look at any questions that need another go.
Tips for parents
- Keep sessions short — five to ten minutes of counting several times a day is better than one long session.
- Count during daily life: stairs, pegs on the washing line, oranges in the fruit bowl.
- If your child gets stuck, count together in a whisper and let them say the last number out loud.