Counting to Twenty

Overview

In this 45-minute early-years lesson, children develop recognition of numerals 1–20 and connect each numeral with a collection of objects. They build on familiar counting songs and small collections by counting forwards and backwards, matching numerals, and explaining how they know how many objects there are.

Learning intentions

• WALT recognise and name numerals from 1 to 20.
• WALT count forwards and backwards between 1 and 20.
• WALT count a collection of up to 20 objects, matching one object to one number.
• WALT show our mathematical thinking using objects, numerals and a number line.

Success criteria

• I can say the numbers from 1 to 20 in order.
• I can count backwards from 20 to 1, with help if I need it.
• I can match a numeral to the correct number of objects.
• I can check my counting by touching or moving each object once.

Prior learning

Children have practised saying numbers in sequence and counting small groups of objects, ideally to 10. Briefly revisit one-to-one counting: each object gets one number word, and the last number tells how many there are.

Vocabulary

number, numeral, count, forwards, backwards, before, after, more, fewer, same, collection, number line

Curriculum links

• Te Mātaiaho Mathematics and Statistics — Number: counting forwards and backwards between 1 and 20.
• Te Mātaiaho Mathematics and Statistics — Number: counting collections up to 20.
• Te Mātaiaho Mathematics and Statistics — Mathsteasers: building challenge and deeper mathematical thinking through accessible problems.

Lesson structure (45 minutes)

1. 0–5 min · Warm-up and hook. Open with the counting hook and warm-up slides and ask, “How many children are hiding behind the curtain?” Display numerals 1–10, then lead a movement count forwards to 20 and backwards from 10; children join in, using fingers or actions to support the sequence.

2. 5–12 min · Explicit modelling. Use the numeral and counting slides to show a large numeral, a floor number line and a matching collection of counters. Model touching each counter once while saying one number word, then model finding the numeral 8 and jumping forwards and backwards along the number line. Think aloud: “I counted 8 objects, so I need the numeral 8.” Highlight that the last number said tells how many objects are in the collection.

3. 12–18 min · Guided practice. Place numeral cards 1–20 where all children can see them. Call out a numeral and invite children to find it, say the number before and after it, and show the number on their fingers where possible. Repeat with gaps in a spoken sequence, for example, “6, 7, __, 9”, then practise short backwards sequences such as 12, 11, 10. Use the before-and-after discussion slides to prompt responses and address common reversals.

4. 18–30 min · Partner collection challenge. Put children in 10 mixed-ability pairs. Give each pair numeral cards, a tray of counting objects and a short floor or desk number line. Partner A turns over a numeral card and says it; Partner B counts out that many objects, touching or moving each one. Both partners check the collection against the numeral and then swap roles. Children make one collection between 1 and 20, then choose a second card. Encourage them to arrange objects in a line or groups so they can check efficiently. Circulate and ask, “How do you know?”, “What number comes next?” and “Can you count back from your number?” Refer to the partner activity instruction slide if pairs need a reminder.

5. 30–38 min · Independent application. Distribute the numeral and counting worksheet. Children complete a short task: trace or name selected numerals 1–20, draw lines to match numerals with collections, fill missing numbers in forwards and backwards sequences, and count one pictured collection. Read instructions aloud and allow children to use a number line and counters. Confer with individuals while others work.

6. 38–45 min · Plenary and formative check. Gather children on the mat and revisit the plenary slides. Show three numerals, including one between 11 and 20, and ask children to make the matching quantity with fingers, counters or an air-drawn number. Invite two children to explain how they checked a collection. Finish with the class counting forwards to 20 and backwards from 10, celebrating careful counting rather than speed.

Resources

• the complete counting deck displayed throughout the lesson
• the numeral and counting worksheet
• Numeral cards 1–20, ideally one set per pair
• Counting objects such as counters, linking cubes or bottle tops
• Number lines showing 1–20
• Ten trays or small baskets for partner materials
• Whiteboard and marker
• Pencils and crayons

Assessment

• During warm-up and guided practice, note which children recognise numerals, join the sequence and identify numbers before or after.
• During partner work, observe one-to-one counting, correct cardinality, numeral matching and whether children can count backwards with or without the number line.
• Use the worksheet and plenary responses as an exit check. Record children who need further practice with numerals 1–10, teen numbers, or backwards counting.

Differentiation

• Support: Begin with numerals 1–10, provide a number line and ten-frame, use larger objects, and count alongside the child. Offer sentence starters: “I have counted ___ objects, so I need ___.”
• Pair children thoughtfully and give one partner the role of mover and the other the role of checker before swapping.
• For children who confuse teen numerals, emphasise the spoken number, visual pattern and position on the number line; avoid requiring writing before they can identify the numeral.
• Extension: Children choose a numeral without looking, make the collection, then place it between the correct neighbouring numerals. Challenge them to count backwards from 20 or explain two ways to check their collection.