Number sence

**Learning outcome: After this course students will find out what numbers are called natural and integer. They shall learn to read them and write them down.**

Introduction

**Natural numbers** include all the whole numbers excluding the number 0., e.g. you may begin at 1 and increase to infinity: 1, 2, 3, 4, 5, etc.

Natural numbers are the same as “counting numbers” because they are used for counting. For example, if you are counting money, you would use natural numbers (usually starting with 1). When written, natural numbers do not have a decimal point (since they are integers), but large natural numbers may be grouped with a space: 1 000 (one thousand) and 234 567 890. (two hundred and thirty four millions five hundred and sixty seven thousand eight hundred and ninety). It makes it easier to read large numbers.

An **integer** (from the Latin integer meaning “whole”) is a number which is not a fraction but also includes all whole numbers, as well as zero, negatives and positives, e.g. -2, -1, 0, 1, 2 are all integers. But numbers like 1.2 or 5/3 are not integers.

A **digit** is a written symbol for any of the ten numbers from 0 to 9. 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 are the ten digits we use in everyday numerals. To write a single-digit numeral we use one digit, two digits in two-digit numerals and so on.

Example:

The numeral 153 is made up of 3 digits (“1”, “5”, and “3”)

Two-digits numerals – 12, 45, 36

Single-digit numerals – 2, 8, 6

The numeral is separated into groups – Millions, thousands, and ones

2 625 310

Millions | Hundreds | Ones |

2 | 625 | 310 |

two million six hundred and twenty-five thousand three hundred and ten

Example: **Number 2, 638**

8 – shows how many ones are there in a numeral

3 – tens

6 – hundreds

2 – thousands