You will learn
- Read and write numbers to 100.
- Show a number as tens and ones.
- Compare two numbers to 100.
- Count on and back in 1s, 2s, 5s and 10s.
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
- Numbers to 100 have tens and ones.
- The tens digit tells how many tens.
- Compare the tens first, then the ones.
- Count in 1s, 2s, 5s and 10s.
Words to know
A symbol 0 to 9 used to write numbers.
Groups of ten.
Single units.
Say which is bigger or smaller.
1. Discover: the market count
A trader has 47 oranges. She packs them in bags of ten. How many full bags can she make, and how many oranges are left over?
2. Understand: tens and ones to 100
A two-digit number has tens and ones. In 47, the 4 means 4 tens (40) and the 7 means 7 ones. So 47 = 40 + 7.
To compare, look at the tens first. 63 is more than 58 because 6 tens is more than 5 tens. If the tens are the same, compare the ones: 63 is more than 61.
We count in 1s, 2s, 5s and 10s: 10, 20, 30, 40 and 5, 10, 15, 20.
Idea 1: Tens and ones
In 47, the 4 means 4 tens (40) and the 7 means 7 ones. So 47 = 40 + 7.
Idea 2: Compare numbers
Look at the tens first. 63 has 6 tens and 58 has 5 tens, so 63 is more. If the tens match, compare the ones.
Why tens first? A ten is worth much more than a one.
Idea 3: Count in steps
Counting on 10 changes the tens digit: 46, 56, 66. Count by 5s: 35, 40, 45. Count by 2s: 14, 16, 18.
3. Worked examples
Example 1 (I show you): Build a number
Write 5 tens and 3 ones as a number.
- 5 tens is 50.
- 50 + 3 = 53.
Answer: 53
Example 2 (We do it together): Which is less
Which is less: 74 or 71?
- Both have 7 tens.
- Compare ones: 1 is less than 4.
Answer: 71
Example 3 (You try): 10 more
What is 10 more than 46?
Show the steps and answer
- 10 more adds 1 to the tens digit.
Answer: 56
Did you know?
The numbers 1 to 100 appear in a hundred square. Each row goes up by 10 as you move down a column.
Why this matters
Knowing numbers to 100 well is the base for adding, subtracting and money.
4. Explore: bundles and sticks
You need 50 sticks or straws and some string.
- Make 4 bundles of ten and 7 single sticks.
- Say and write the number: 47.
- Make 38 with bundles and sticks.
- Say which is more, 47 or 38, and why.
Think about it: what did you notice?
47 is 4 tens and 7 ones; 38 is 3 tens and 8 ones. 4 tens is more than 3 tens.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- The digit ___ means ___ tens.
- ___ is more than ___ because ___.
- 10 more than ___ is ___.
- I count in ___s.
Guided practice
Question 1. What is the value of the 6 in 62?
60 (6 tens).
Question 2. Which is more: 58 or 63?
63; 6 tens is more than 5 tens.
Question 3. Count on by 5s: 35, 40, __
45.
Independent practice
Level 1: Start
- Write 5 tens and 3 ones as a number.
- Which is less: 74 or 71?
- What number is 10 more than 46?
- Count back by 10s from 90 to 50.
- Write 29 as tens and ones.
Level 2: Grow
- 6 tens and 4 ones is ___.
- What is 10 less than 83?
- Put in order, smallest first: 45, 54, 39.
Level 3: Stretch
- What is 1 more than 79?
- Count by 5s from 15 to 40.
- Sade says 38 is more than 83 because 8 is more than 3. What is wrong?
Answers are in the answer key below. Try first, then check.
6. Apply: everyday mathematics
A baker packs 34 loaves. She has 29 more. Does she have more than 60 loaves?
Show a sample answer
34 + 29 = 63. Yes, 63 is more than 60.
Another one. A box holds 10 pens. A shop has 7 full boxes and 6 loose pens. How many pens is that?
Show a sample answer
76
7. Common mistakes
Fix: The 5 means 5 tens, which is 50.
Fix: Compare the tens first.
Fix: Say forty-seven: 4 tens and 7 ones.
8. Lesson summary and revision card
- I can read and write numbers to 100.
- I can show a number as tens and ones.
- I can compare two numbers.
- I can count in 1s, 2s, 5s and 10s.
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
- Two-digit numbers have tens and ones.
- Compare tens first.
- Count in 1s, 2s, 5s and 10s.
11. Next lesson
Next lesson: Counting hundreds. 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.
- Write 5 tens and 8 ones as a number. [1 mark]
- Which is greater, 67 or 76? [1 mark]
- What is 10 more than 54? [1 mark]
- Count back in tens from 100 to 60. [2 marks]
- Explain why 45 is less than 54. [2 marks]
Total: 7 marks.
Marking guide and model answers
- 58 [1]
- 76 [1]
- 64 [1]
- 100, 90, 80, 70, 60 [2]. Give 1 mark for one error.
- 45 has 4 tens and 54 has 5 tens [1]; 4 tens is less than 5 tens [1]
Score guide: 6 to 7 = secure. 5 to 5 = nearly there, revise the parts you missed. Under 5 = work through the lesson again with a grown-up.
Printable worksheet
- Write 6 tens and 4 ones.
- Which is less: 74 or 71?
- 10 more than 46?
- Value of the 9 in 91?
- Count on by 2s: 20, 22, __
- 3 tens and 7 ones = ___.
- Which is bigger: 62 or 26?
- 10 more than 90 is ___.
- Count by 5s: 50, 55, __.
- Write 84 as tens and ones.
Homework
Collect 50 small objects (stones or beans). Make bundles of ten and show a number.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| Write 6 tens and 4 ones. | 64 | 2 |
| Which is less: 74 or 71? | 71 | 2 |
| 10 more than 46? | 56 | 2 |
| Value of the 9 in 91? | 90 | 2 |
| Count on by 2s: 20, 22, __ | 24 | 2 |
| Total | 10 |
Practice answers: Worksheet: 1 64; 2 71; 3 56; 4 90; 5 24.
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 37; 7 62; 8 100; 9 60; 10 8 tens and 4 ones.
Independent practice answers. Level 1: 1 53; 2 71; 3 56; 4 90, 80, 70, 60, 50; 5 2 tens and 9 ones. Level 2: 1 64; 2 73; 3 39, 45, 54. Level 3: 1 80; 2 15, 20, 25, 30, 35, 40; 3 Compare the tens first. 83 has 8 tens and 38 has 3 tens, so 83 is more..
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Read and write numbers to 100 | 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 Show a number as 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 |
| O3 Compare two numbers to 100 | 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 Count on and back in 1s, 2s, 5s and 10s | 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: Reading 52 as 5 and 2 only. The 5 means 5 tens, which is 50.
- Explain another way: use real objects first, then pictures.
- Show a simpler example: Make numbers with bundles of ten and single sticks, then say the tens and ones.
- 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 reviews numbers to 100 using tens and ones. You do not need to be good at mathematics to help.
- Use bundles of 10 sticks and loose sticks to show numbers.
- Ask: which is more, 53 or 35? Why?
- Count in 2s, 5s and 10s on walks.
- 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: read and write numbers to 100; show a number as tens and ones; compare two numbers to 100; count on and back in 1s, 2s, 5s and 10s.
Prerequisite knowledge. Grade 1 numbers to 100.
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 50 sticks or straws and some string. 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 tens? How many ones? Which is more? How do you know?
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. Reading 52 as 5 and 2 only. The 5 means 5 tens, which is 50.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz and worksheet on this page. The 7-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 numbers with bundles of ten and single sticks, then say the tens and ones. 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 2 » 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 2.NBT.A (place value) and 1.NBT.B; Cambridge Primary Mathematics Stage 2 (number and place value). These sources informed the lesson.