Number Names and Number Sense (4-digit numbers)

Number

A fundamental component of mathematics is numbers. This article will introduce the four-digit numbers and their operations to the students.

In everyday life, numbers are everywhere. Usually, the key to recognising the number is something called "number sense".

1000 is the smallest four-digit number and one thousand is the name we read it.

9999 is the largest four-digit number and nine thousand nine hundred and ninety-nine is the name we read it.

Four-Digit Numbers

If a number has only four digits, it is said to have a 4-digit number. The first digit in a 4-digit number must be 1 or more and the other digits might range from 0 to 9.

For example, 5098, 3467 and 2587 are four-digit numbers.

The digits 0 through 9 can be used to create a variety of four-digit numbers but we must keep in mind that the thousand places should never be 0.

For example, 0579 is considered a three-digit number rather than a four-digit number. The number 0579 is considered as 579.

The numerals are arranged from right to left at the ones, tens, hundreds and thousands according to their values.

Take 7946 as an example.

The expanded form of the number 7946 is:

7000 + 900 + 40 + 6

We know that:

7000 = Seven thousand (7 thousand)

900 = Nine hundred (9 hundred)

40 = Forty (4 tens)

6 = Six (6 ones)

When you put it all together, it looks like this:

7946 = Seven thousand nine hundred and forty-six.

Natural Numbers

Natural numbers are all positive numbers. They do not have any zero or negative numbers. They are also known as counting numbers because they are used to count things.

For example, 2 is a natural number
75 is a natural number
0 is not a natural number
-5 is not a natural number

Odd Numbers

Odd numbers are natural numbers that cannot be completely divided by 2. It cannot be evenly divided into two different numbers. An odd number will leave a remainder when divided by 2. A few examples of odd numbers are 1, 3, 5, 7, 9 and 11.

Example:How many odd numbers are there between 1 and 500?

a) 150
b) 200
c) 250
d) 500

Answer: c) 250

Explanation: There are 500 natural numbers between 1 and 500. Out of these, there are 250 odd numbers and 250 even numbers between 1 and 500.

Even Numbers

Even numbers are natural numbers that can be divided by 2 perfectly. Even numbers always have the last digit as 0, 2, 4, 6 or 8. 

A few examples of even numbers are 2, 4, 6, 8, 10, 12 and 14.

Unitary Method

The unitary method involves a mathematical problem solved by determining the value of a single unit and then multiplying that value to determine the required value.

For example: If the cost of 3 toys is $30, we may get the price of 1 toy by dividing the quantities.

Cost of 3 toys = $30

Cost of 1 toy = $30 3 = $10

We determine the price of 1 toy which is $10.

By simply multiplying, we can utilise this method to determine the value of 5 toys.

Cost of 1 toy = $10

Cost of 5 toys = $10 × 5 = $50

Therefore, 5 toys cost $50.

Example: If the monthly rent for parking to keep a luxury car is $1500, what is the rent for 9 months?

a) $10500
b) $11500
c) $12500
d) $13500

Answer: d) $13500

Explanation: Rent for 1 month = $1500
Rent for 9 months = $1500 9 = $13500

Roman Number

Roman numerals are still used today to represent fixed positive numbers. To express the fixed positive numbers in Roman numerals, alphabets are used. These Roman numerals for 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 are I, II, III, IV, V, VI, VII, VIII, IX and X, respectively.

Roman Numbers 1–100 are shown

Ascending Order

Numbers can be arranged in ascending order from smallest to biggest value. The arrangement is left to right. Increasing order is another name for ascending order.

For example, the numbers 61, 15 and 30 can be arranged as follows in ascending order: 15, 30 and 61.

Example: Which of the following is arranged in ascending order?

a) 1743, 2918, 2917, 7518, 7537
b) 1743, 2918, 7518, 2917, 7537
c) 1743, 2917, 2918, 7518, 7537
d) 1743, 2917, 2916, 7518, 7537

Answer: c) 1743, 2917, 2918, 7518, 7537

Explanation: Numbers can be arranged as 1743, 2917, 2918, 7518 and 7537 in ascending order.

Descending Order

Numbers can be arranged in descending order from biggest to smallest value. Decreasing order is another name for descending order.

For example, the numbers 61, 15 and 30 can be arranged as follows in descending order: 61, 30 and 15.