Class 07 NCERT Chapters

All organisms need food and utilise it to get energy for growth and maintenance of their body. Green plants synthesise food for themselves by the process of photosynthesis. They are autotrophs.

The circle, the square, the rectangle, the quadrilateral and the triangle are examples of plane figures; the cube, the cuboid, the sphere, the cylinder, the cone and the pyramid are examples of solid shapes.

A figure has line symmetry, if there is a line about which the figure may be folded so that the two parts of the figure will coincide.

Very large numbers are difficult to read, understand, compare and operate upon. To make all these easier, we use exponents, converting many of the large numbers in a shorter form.

Algebraic expressions are formed from variables and constants. We use the operations of addition, subtraction, multiplication and division on the variables and constants to form expressions.

Perimeter is the distance around a closed figure whereas area is the part of plane occupied by the closed figure.

A number that can be expressed in the form p/q, where p and q are integers and q ≠ 0, is called a rational number.

We are often required to compare two quantities in our daily life. They may be heights, weights, salaries, marks, etc. While comparing heights of two persons with heights 150 cm and 75 cm, we write it as the ratio 150 : 75 or 2 : 1.

The six elements of a triangle are its three angles and the three sides.

A line-segment has two end points. A ray has only one end point (its initial point); and a line has no end points on either side.

An equation is a condition on a variable such that two expressions in the variable should have equal value. The value of the variable for which the equation is satisfied is called the solution of the equation.

The collection, recording and presentation of data help us organise our experiences and draw inferences from them. Before collecting data we need to know what we would use it for.

Two fractions are multiplied by multiplying their numerators and denominators separately. The product of two proper fractions is less than each of the fractions that are multiplied.

Integers are a bigger collection of numbers which is formed by whole numbers and their negatives. Integers are closed for addition and subtraction both. That is, a + b and a - b are again integers, where a and b are any integers.