You will learn
- Make groups of ten from a pile of objects.
- Count the groups of ten.
- Count the leftover ones.
- Say how many in all using tens and ones.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Make groups of ten from a pile.
- Count the groups of ten.
- Count the leftover ones.
- 23 is 2 tens and 3 ones.
Words to know
Ten things together.
Things tied or grouped together.
Fewer than ten that remain.
Single things.
1. Discover: bundling sticks
A farmer has a big pile of sticks. Counting one by one is slow. What if she ties them in bundles of ten?
2. Understand: grouping into tens
To count a big pile, make groups of ten. Put 10 together in each group. Count the groups, then count the ones that are left over.
If there are 3 groups of ten and 4 left over, we say 3 tens and 4 ones: that is 34.
Counting in tens is much quicker than counting one by one.
Idea 1: Make groups of ten
You have 23 sticks. Tie 10 together. Tie another 10. Three sticks are left over.
Why? Counting groups of ten is faster, and you make fewer mistakes.
Idea 2: Count the tens, then the ones
Count the tens: 10, 20. Then count the ones: 21, 22, 23. There are 23 sticks.
Idea 3: Say it with tens and ones
23 is 2 tens and 3 ones. Leftovers fewer than ten are always ones.
3. Worked examples
Example 1 (I show you): 34 seeds
There are 34 seeds in a pile. Count them in tens.
- Make groups of 10: you can make 3.
- Count the tens: 10, 20, 30.
- Count the 4 leftover ones: 31, 32, 33, 34.
Answer: There are 34 seeds.
Example 2 (We do it together): Groups of ten
How many are in 4 groups of ten?
- Count in tens: 10, 20, 30, 40.
Answer: 40
Example 3 (You try): Tens and ones
There are 2 groups of ten and 5 leftover. How many in all?
Show the steps and answer
- 2 tens is 20.
- Count on 5 ones: 21, 22, 23, 24, 25.
Answer: 25
Did you know?
Shopkeepers often pack things in tens or dozens so they can count them quickly. Eggs come in boxes of 6, 10 or 12.
Why this matters
Counting in tens is faster and has fewer mistakes than counting by ones.
4. Explore: make bundles
You need 30 or more small objects (sticks, seeds, stones).
- Take a handful of objects and count out 10. Make a group.
- Make as many groups of ten as you can.
- Count the groups of ten, then the leftovers.
- Write: __ tens and __ ones.
Think about it: what did you notice?
For example 2 groups of ten and 5 leftover is 25.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- There are ___ groups of ten and ___ ones.
- ___ tens and ___ ones makes ___.
- I count in tens: ___, ___, ___.
- Then I count the ones: ___.
Guided practice
Question 1. 3 groups of ten and 2 left over. How many?
32.
Question 2. How many objects in 4 groups of ten?
40.
Question 3. Why make groups of ten?
To count faster and avoid mistakes.
Independent practice
Level 1: Start
- Count in tens: 10, 20, __, __.
- What is 2 tens and 6 ones?
- Draw 3 groups of ten (use lines) and 1 one.
- How many tens are in 40?
- Explain how to count 23 sticks quickly.
Level 2: Grow
- How many are in 5 groups of ten?
- 3 groups of ten and 6 leftover is…
- Draw 2 groups of ten and 4 ones. Write the number.
Level 3: Stretch
- There are 47 seeds. How many full groups of ten and how many are left?
- Ben counts 3 tens and 12 ones. Make as many tens as you can. What is the number?
- How many groups of ten can you make from 30 sticks? Count in tens.
Answers are in the answer key below. Try first, then check.
6. Apply: everyday mathematics
A seller has 26 mangoes. How can she pack them in bags of ten? How many bags and how many loose?
Show a sample answer
2 bags of ten and 6 loose mangoes.
Another one. A shop packs mangoes in bags of 10. It has 38 mangoes. How many full bags can it fill, and how many mangoes are left?
Show a sample answer
3 full bags and 8 mangoes left.
7. Common mistakes
Fix: Each group is ten. 3 groups of ten is 30.
Fix: Only a full group of ten counts as a ten. Fewer than ten are ones.
Fix: Check each group has ten before counting in tens.
8. Lesson summary and revision card
- I can make groups of ten from a pile.
- I can count the groups of ten.
- I can count the leftover ones.
- I can say how many in all using tens and ones.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Make groups of ten to count a big pile.
- Count the tens, then the ones.
- 3 tens and 4 ones is 34.
11. Next lesson
Next lesson: Understanding ones. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- How many are in 6 groups of ten? [1 mark]
- Write the number for 3 groups of ten and 8 ones. [1 mark]
- There are 43 stones. How many full groups of ten can you make? How many stones are left? [2 marks]
- Draw 2 groups of ten and 6 ones using lines and dots. Write the number. [3 marks]
- Why is counting in tens quicker than counting by ones? [2 marks]
Total: 9 marks.
Marking guide and model answers
- 60 [1]
- 38 [1]
- 4 groups [1]; 3 left [1]
- 2 tens drawn [1]; 6 ones [1]; 26 [1]
- You count fewer groups [1]; there are fewer mistakes [1]
Score guide: 8 to 9 = secure. 6 to 7 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- How many in 2 tens?
- How many in 5 tens?
- 3 tens and 4 ones = __
- 45 is __ tens and __ ones. (write both)
- How many tens in 30?
- How many are in 7 groups of ten?
- 2 groups of ten and 7 leftover is…
- How many tens are in 40?
- There are 15 seeds. How many groups of ten and how many are left?
- Write 4 tens and 4 ones.
Homework
Collect 25 to 40 small things at home. Make groups of ten and count the leftovers. Tell a family member the total.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| How many in 2 tens? | 20 | 2 |
| How many in 5 tens? | 50 | 2 |
| 3 tens and 4 ones = __ | 34 | 2 |
| 45 is __ tens and __ ones. (write both) | 4 tens 5 ones | 2 |
| How many tens in 30? | 3 | 2 |
| Total | 10 |
Practice answers: Worksheet: 1 20; 2 50; 3 34; 4 4 tens 5 ones; 5 3.
Quiz answers: 1 A, 2 B, 3 C, 4 A, 5 B, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 C, Challenge 2 C.
Extra worksheet answers (items 6 onward): 6 70; 7 27; 8 4; 9 1 group of ten and 5 left; 10 44.
Independent practice answers. Level 1: 1 30, 40; 2 26; 3 3 lines and 1 dot; 4 4; 5 make 2 groups of ten and count the 3 left: 10, 20, 21, 22, 23. Level 2: 1 50; 2 36; 3 24. Level 3: 1 4 groups of ten and 7 left; 2 12 ones is 1 ten and 2 ones. So 4 tens and 2 ones: 42.; 3 3 groups: 10, 20, 30..
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Make groups of ten from a pile of objects | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Count the groups of ten | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Count the leftover ones | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Say how many in all using tens and ones | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: Counting the groups of ten as ones (3 groups = 3). Each group is ten. 3 groups of ten is 30.
- Explain another way: use real objects first, then pictures.
- Show a simpler example: Make one group of ten with counters and count the leftovers up to 9.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child makes groups of ten to count a pile quickly. You do not need to be good at mathematics to help.
- Count beans, stones or sticks. Make piles of ten.
- Count the piles of ten, then the ones left.
- Ask: how many tens? How many ones?
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: make groups of ten from a pile of objects; count the groups of ten; count the leftover ones; say how many in all using tens and ones.
Prerequisite knowledge. Unit 1: numbers to 100 and tens and ones.
Materials. Counters (stones, seeds or bottle tops), paper, pencils, board or chalkboard. Low-resource options: use stones, seeds, sticks, bottle tops or drawings in the sand or on the board instead of printed materials.
Preparation. Gather the counters and draw the example pictures on the board before the lesson.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Start with the Discover situation and let learners suggest ideas before you teach.
Explanation (10 min). Teach the Understand section with real objects first, then pictures, then symbols and words.
Guided activity (10 min). You need 30 or more small objects (sticks, seeds, stones). Learners follow the Explore steps in pairs.
Independent activity (10 min). Learners complete the independent practice and the worksheet.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. How many groups of ten can you make? How many are left? How do you say the number?
Teacher explanation notes. Use the concrete, pictorial, abstract order: real objects first, then pictures, then symbols and words. Return to real objects whenever a learner needs support.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and work with a partner; say each step aloud together. Extension. Ask learners to make up their own example and explain it to a partner.
Formative assessment. Listen to learner explanations, ask “how do you know?”, and check the independent work.
Misconceptions. Counting the groups of ten as ones (3 groups = 3). Each group is ten. 3 groups of ten is 30.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz and worksheet on this page. The 9-mark exam practice scheme, the 10-mark scheme and all answers are in the answer sections above. Re-check every answer and the marking scheme before publication.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Make one group of ten with counters and count the leftovers up to 9. Enrichment. Invite learners to find or create three more examples at home or in the classroom and explain them. Homework. See above.
Teacher reflection. After teaching, record: which concepts learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points named in the Courseversity standard: Common Core State Standards for Mathematics, Cambridge Primary and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Official standards for this topic area. Common Core State Standards for Mathematics (official site): Grade 1 » Number & Operations in Base Ten. These pages list the standards that cover this topic area; read them alongside the lesson.
Research used to shape this lesson. Common Core 1.NBT.B.2 (bundling tens); Cambridge Primary Mathematics Stage 1. These sources informed the lesson.