Numbers 1 to 100: Class 1 Study Guide
Numbers help us count things and tell 'how many'. In Class 1 children learn to count up to 100.
Counting begins with numbers 1 to 10, then 11 to 20, and gradually extends to 100. Each number comes after one number and before another. The number after 7 is 8, the number before 7 is 6, and 7 is between 6 and 8. Children should be able to count objects by touching each one and saying the number names in order.
From 11 onwards, numbers are made of tens and ones. The number 23 means 2 tens and 3 ones. Understanding this is the first step in understanding place value.
Tens and ones
Group objects in bundles of ten. 10 sticks tied together make a bundle (one ten). The number 34 is three bundles of ten and four single sticks.
| Number | Tens | Ones | How to say it |
|---|---|---|---|
| 12 | 1 | 2 | twelve |
| 25 | 2 | 5 | twenty-five |
| 40 | 4 | 0 | forty |
| 99 | 9 | 9 | ninety-nine |
Counting by tens
Counting by tens is quicker than by ones: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100. A hundred chart shows 10 rows of ten. Patterns appear: numbers in the same column end in the same digit.
More than, less than
Numbers with more tens are greater. 47 is greater than 39 because 4 tens is more than 3 tens. If the tens are the same, compare the ones. Use the signs > (greater than) and < (less than), but in Class 1 many teachers use words like 'more' and 'less'.
Which number has more?
Compare the ones digits.
56 is less than 65.
Worked examples and common mistakes
Example: What is the number after 59? 60. Example: Which is smaller, 18 or 81? 18. Common mistakes: mixing up numbers whose digits are reversed (13 and 31, 16 and 61), missing a number when crossing a tens boundary (29 to 30), and writing digits backwards. Use bundles of sticks or a bead frame to show the tens clearly.
Check your understanding: model answers
1. 50. 2. 62 is more, because 6 tens is more than 2 tens. 3. 35.
✨ Key Takeaways
- Numbers have a place in order: before, after and between.
- Numbers beyond 10 are made of tens and ones.
- Count by tens to move quickly.
- More tens means a greater number.
💬 Questions for Discussion & Reflection
- Write the number that comes after 49.
- Is 62 more or less than 26?
- Write 3 tens and 5 ones as a number.