### Other Chapters For 7th

• 7th-class Science Chapter 28

Energy is an important ingredient in all phases of society. We live in a very interdependent...
• 7th-class Science Chapter 27

Heat transfer is a discipline of thermal engineering that concerns the generation, use,...
• 7th-class Science Chapter 26

forms of energy: thermal (heat), light, electrical, sound, kinetic, chemical, nuclear and...
• 7th-class Science Chapter 25

Energy cannot be created or destroyed, only converted from one form to another. These...
• 7th-class Science Chapter 24

In everyday use and in kinematics, the speed of an object is the magnitude of its velocity (the...
• 7th-class Science Chapter 23

In physics, a moment is an expression involving the product of a distance and a physical...
• 7th-class Science Chapter 22

At terminal velocity the gravitational force down equals the air resistance force up. vehicle...
• 7th-class Science Chapter 21

The density, or more precisely, the volumetric mass density, of a substance is its mass per unit...
• 7th-class Science Chapter 20

Measurement is the assignment of a number to a characteristic of an object or event, which can...
• 7th-class Science Chapter 19

The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic...

# 7th Class Chapter No 18 - Calculations and mental strategies in Maths for IGCSE

Mental calculation or mental maths is an old mathematical tool. It is doing maths without using any tools or writing anything down. Mental calculation uses only the human brain. People who use mental maths use shortcuts to make the calculation easier. People who do mental calculation do it without a computer or a calculator. Mental calculation often involves the use of specific techniques devised for specific types of problems. There are specific methods for adding, subtracting, multiplying or dividing and more calculations such as squaring numbers or its opposite [square] "root finding". And even specific methods depending on the numbers used, such as "multiply by 10" or "multiply any 2-digit numbers", or "square numbers near 50".
Posted in 7th on February 13 2019 at 03:29 PM

### IGCSE 7th CLASS Maths OTHER CHAPTERS

• 7th-class Maths Chapter 28

Statistics is a branch of mathematics dealing with the collection, analysis, interpretation,...
• 7th-class Maths Chapter 28

Division is one of the four basic operations of arithmetic, the others being addition,...
• 7th-class Maths Chapter 27

n probability theory, an experiment or trial (see below) is any procedure that can be infinitely...
• 7th-class Maths Chapter 26

The only difference between cubes and cuboids is the shape of the six faces. Each face of...
• 7th-class Maths Chapter 25

In calculus, integration by substitution, also known as u-substitution, is a method for finding...
• 7th-class Maths Chapter 24

Proportionality may refer to: Proportionality (mathematics), the relationship between two...
• 7th-class Maths Chapter 23

Probability is the measure of the likelihood that an event will occur. See glossary of...
• 7th-class Maths Chapter 22

The 'perimeter' of a shape is the distance around it. In order to calculate the perimeter of a...
• 7th-class Maths Chapter 19

A fraction (from Latin fractus, "broken") represents a part of a whole or, more generally, any...
• 7th-class Maths Chapter 17

In mathematics, transformation geometry (or transformational geometry) is the name of a...