Profile
Settings
Refer your friends
Sign out
Definition of a number line is a horizontal line consisting of numbers placed at equal intervals. The numbers can be integers, whole numbers, real numbers, or decimals. The number line is a never-ending line from −∞ to +∞ , consisting of both positive and negative integers on the number line. John Wallis first mentioned the number line concept in his Treatise of algebra. According to him, the addition and subtraction on the number line are done by moving forward or backward, respectively. It is the most useful tool for comparing numbers and performing operations. There are several real-life examples where the concept of a number line is used.
Characteristics of the number line
The 0 is considered the origin of the number line
The negative numbers are always placed on the left-hand side of 0, and the positive numbers are always placed on the right-hand side of the 0 on the number line
In the number line, the numbers are present in increasing order from left to right; that is, -6 placed on the left of -5 is smaller than the number
It is also interesting that decimals can also be plotted on the number line with proper intervals and markings
The way of representing numbers on a number line makes it easy to visualise numbers and perform mathematical calculations
Decimals on the Number line
Decimals are a type of fraction that can also be represented on the number line. It is similar to the representation of fractions on the number line. Decimal numbers are a combination of an integral part and a fractional part separated by a dot. The decimals are placed between the integers on the number line.
Inequalities on the Number line
The expressions with inequality symbols can also be plotted on a number line. For example, for plotting an expression 1<x≤6, we would draw an open circle in the number line at number 1, which means that the number 1 is not included, and at number 6, we would draw a closed circle indicating that the numbers up to 6 the number 6 is itself included.
Drawing a number line
The number line can be drawn in easy 4 steps;
In the first step- a horizontal line is drawn with arrows on both sides, indicating that the lines are non-ending and increase to infinity on both sides
In the second step- a proper scale is chosen for drawing the number line. If a number like 50 or 20 needs to be plotted on a number line, then a scale of multiple of 5 can help plot the number
Third step- the most important step is to make sure that the points are marked at equal intervals
The fourth step- the last step is to locate the desired number on the number line and then highlight or circle it for reference
Real-life uses of a number line
Most mechanical devices like rulers, barometers, pressure gauges, and bathroom scales are based on the concept of the number line where the instruments are marked for measuring the lengths of objects and various other purposes
Another classic use of the number line is the thermometer which tells us about the temperature of any substance
The number line is also used in calculating the distance travelled by vehicles
Conclusion
Numbers that play a very important role in our daily lives to count, measure, or label objects can be easily represented in a horizontal line; this is a number line. Children use the number line to learn addition and subtraction easily. The number line consists of both positive and negative integers on the right-hand and left-hand sides of the origin. There is a different process for adding positive and negative integers on a number line. Generally, such operations are easily performed by either moving towards the number line’s left or right side—the importance of number lines to help in addition, subtraction, and comparison between integers and numbers. The concept of the number line is also applicable in real-life examples like a thermometer, barometer, scale, protractor, ruler, and many more such instruments.
