Learning Objectives
- Work with numbers up to 100
- Count in groups of tens and ones
- Write numbers in words and numerals
- Arrange numbers in order from smallest to biggest
- Find numbers that come before, after, and between
Key Concepts
Numbers from 51 to 100
After 50, we continue counting: 51, 52, 53, and so on up to 100. The number 51 means 5 tens and 1 one. The number 73 means 7 tens and 3 ones. The number 100 is a very special number made of 10 tens.
Place Value
In a two-digit number, the left digit shows tens and the right digit shows ones. In 46, the 4 is in the tens place and means 40. The 6 is in the ones place and means 6. So 46 = 40 + 6.
Before, After, and Between
The number just before 56 is 55. The number just after 56 is 57. The number between 56 and 58 is 57. We can practise this by counting on a number line or a number chart.
Ordering Numbers
We can put numbers in order from smallest to biggest. This is called ascending order. For example: 23, 45, 67, 89. We can also put them from biggest to smallest, called descending order: 89, 67, 45, 23.
The Number 100
100 is a three-digit number. It is the smallest three-digit number. It is made of 1 hundred, 0 tens, and 0 ones. 100 = 10 tens = 100 ones. It is 1 more than 99.
Important Terms
- Place value: The value of a digit based on its position in the number
- Ascending order: Arranging numbers from smallest to largest
- Descending order: Arranging numbers from largest to smallest
- Hundred: The number 100, which equals 10 tens
- Number chart: A chart showing numbers arranged in rows and columns
Quick Revision
- Numbers from 51 to 100 continue the pattern of tens and ones
- In a two-digit number, the left digit is tens and the right digit is ones
- 100 is the first three-digit number
- Ascending order means small to big; descending order means big to small
- Practice: What comes before 78? (77) What comes after 99? (100)
- Use a number chart from 1 to 100 to practise counting and patterns