Whole Numbers

Numbers to 20

What will we learn today?

• Count, read and write numbers • Comparing and ordering numbers• Number patterns• Place Values

Introduction to Numbers

Number can be written in numerals or in words.Numerals – 1, 2, 3, ………….Words – one, two, three, ………

1 digit numbers – 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

2 digit numbers – 10, 11, 12,…………….....99

Let’s count the items below.

There are 12 pencils.

How do we express the number?

Numeral : 12Words : twelve

There are 3 books.

How do we express the number?

Numeral : 3Words : three

1

2

3

1 2 3 4 5 6 7 8 9 10 11 12

Arrange the numbers in order.Begin with the greatest.

4 10 13 17

17, 13, 10, 4greatest

Arrange the numbers in order.Begin with the smallest.

8 16 11 5

5, 8, 11, 16smallest

Complete the number patterns.

+1

+1

+1

+1

2 3 64 5

-2 -2 -2 -2

14 12 810 6

One more example for you.

Place Values

Place Value Chart

Tens Ones

0 8

= 1 unit

0 ten 8 ones = 8

8 ones = 8

Place value is the value of a digit depending on its place in a number.

8 units are not enough to make a group of ten, so it has 1 place value, that is the ones place.

8

7 = 0 ten 7 ones

Place Value Chart

Tens Ones

0 7

Since 7 units are not enough to make a group of ten and number 7 is a single digit number, it has 1 place value that is the ones place.

For the ones place value, it is only fit for a single digit number; number 1-9.

7

One more example for you.

Place Value Chart

Tens Ones

1 0

1 ten 0 ones =101 ten = 10

10 ones = 10

= 10 (base ten or 1 group of 10)

Every number in a two digit number has a different place value. Number 10 is a 2 digit number, therefore digit 0 is in the ones place and the digit 1 is in the tens place.

Here’s another example.

Here’s another example.

Place Value Chart

Tens Ones

1 3

1 ten 3 ones = 13

10 3

1 group of ten

Are you ready to try out the questions?