Definitions and Examples of Math Terms Starting With O
1, 2, 3, 4, 5, …… You can read these numbers easily, right? What is the first number? It is ONE— o-n-e, one. Isn’t it? Maths starts with the number “1”. Now, you can imagine how important the letter ‘O’ is in Mathematics.
Though the numbers start with 0, can you recall the number series taught to you in your school? Or, how did your mother teach you counting? So, in general, the counting begins with “1”.
Many other important words begin with the alphabet O. A list of Maths words that start with O is given below. Add them to your vocabulary and become a pro in Mathematics.
Lists of Maths Words that Begin with the Letter ‘O’
1. One: One is the smallest natural number. It is written as ‘1’ in numbers. It represents a single unit or quantity. It lies between 0 and 2.
2. Odd Numbers: The numbers which are not divisible by 2 are called odd numbers. The series of 1, 3, 5, 7, …. is a series of odd numbers. When these numbers are divided by 2, they leave 1 as a remainder.
3. Octagon: A plane figure which has 8 sides is called an Octagon. It has eight vertices and 8 angles. Also, the prism which is bounded by the 2 octagonal bases and 8 square sides is called an octagonal prism. It has 16 vertices and 12 edges.
4. Obtuse Angle: The angle which is greater than 90° and less than 180° is called the obtuse angle. The triangle in which one angle measures more than 90°, i.e., an obtuse angle is called an obtuse triangle.
Examples of Obtuse Triangle
5. Open Figure: Unlike a closed figure like a triangle, or quadrilateral, there are some figures in which one of the line segments or curves do not meet. These figures do not have any starting or ending point. Some examples of the open figure are shown in the below figure.
Example of Open Figure
6. Ounce: In general, an ounce is referred to as a very small amount of something. In the United States, it is used to measure weight. There are 16 ounces in the pound and it is equivalent to 28.35 grams. Ounces is abbreviated as oz.
7. Origin: Origin is the point from which coordinates are measured. It is the point at which the X- and Y-axis meet and is generally considered as (0, 0).
8. Order: Order shows the arrangement of different items or sequences with each other following a particular pattern or sequence. Also, the degree of an equation, expression, etc. is denoted by an ordinal number. In matrices, the order is referred to as the number of rows and columns. In the differential equation, the order of an equation is referred to as the number of differentiation required to reach the highest derivatives.
Do You Know?
The sum of two odd numbers is always an even number whereas the product of two odd numbers always results in an odd number.
Number 0 is an even number.
Conclusion
In this article, we have learned about the Mathematical words that start from the letter ‘O’. These words will help you to improve your vocabulary. To learn more about such words and enhance your vocabulary, explore our website.
FAQs on List of Math Words That Begin With O
1. What is a math word that starts with O?
A common math word that starts with O is octagon, which is a polygon with eight sides and eight angles. In mathematics, many important terms begin with O, such as:
- Octagon – an 8-sided polygon
- Obtuse angle – an angle greater than 90°
- Odd number – a number not divisible by 2
- Origin – the point (0, 0) on a coordinate plane
- Order of operations – the rule for evaluating expressions
These terms are commonly used in geometry, arithmetic, and algebra.
2. What is an octagon in math?
An octagon is a polygon with 8 sides and 8 interior angles. The sum of the interior angles of an octagon is calculated using the formula (n − 2) × 180°:
- For n = 8
- (8 − 2) × 180° = 6 × 180° = 1080°
A regular octagon has all sides and angles equal, with each interior angle measuring 135°.
3. What is an obtuse angle?
An obtuse angle is an angle that measures more than 90° but less than 180°. It is wider than a right angle but not as wide as a straight angle.
- Example: 120° is an obtuse angle
- 90° is a right angle (not obtuse)
- 180° is a straight angle
Obtuse angles are commonly studied in geometry when classifying triangles and polygons.
4. What is an odd number in math?
An odd number is a whole number that is not divisible by 2. When divided by 2, it leaves a remainder of 1.
- Examples: 1, 3, 5, 7, 9
- General form: 2n + 1 (where n is an integer)
Odd numbers alternate with even numbers on the number line.
5. What is the origin in a coordinate plane?
The origin is the point where the x-axis and y-axis intersect, and its coordinates are (0, 0). It represents the starting point of a Cartesian coordinate system.
- x-coordinate = 0
- y-coordinate = 0
All other points on the graph are measured relative to the origin.
6. What is the order of operations in math?
The order of operations is the rule that tells you the correct sequence to evaluate a mathematical expression: PEMDAS.
- P – Parentheses
- E – Exponents
- M/D – Multiplication and Division (left to right)
- A/S – Addition and Subtraction (left to right)
Example: 3 + 2 × 4 = 3 + 8 = 11, not 20.
7. What does opposite mean in math?
In math, opposite usually means the same distance from zero on a number line but in the opposite direction. Opposites are also called additive inverses.
- The opposite of 5 is −5
- The opposite of −8 is 8
- a + (−a) = 0
Opposites are important when working with integers and solving equations.
8. What is an ordered pair in math?
An ordered pair is a pair of numbers written as (x, y) that represents a point on a coordinate plane. The first number is the x-coordinate, and the second is the y-coordinate.
- Example: (3, 4)
- Move 3 units right (x)
- Move 4 units up (y)
Ordered pairs are used in graphing linear equations and functions.
9. What is an operation in mathematics?
An operation in mathematics is a calculation process such as addition, subtraction, multiplication, or division. Operations combine numbers to produce a result.
- Addition: 4 + 3 = 7
- Subtraction: 9 − 2 = 7
- Multiplication: 3 × 5 = 15
- Division: 12 ÷ 4 = 3
More advanced operations include exponents, roots, and logarithms.
10. What is an obtuse triangle?
An obtuse triangle is a triangle that has one angle greater than 90°. The other two angles must be acute.
- Example: angles of 110°, 40°, and 30°
- The sum of angles in any triangle is 180°
Triangles are classified as acute, right, or obtuse based on their largest angle.
