Original, student-friendly mathematics concept articles covering Number, Algebra, Geometry, Calculus, Proof and competition problem-solving. Written by Dr. Pankaj Jha, founder and Mathematics Educator at SelexIQ.
Rounding replaces a number with a simpler approximate value. Identify the rounding digit, look at the next digit, and round up if it is 5 or more, otherwise leave it. Significant figures count all non-zero digits, zeros between significant digits, and trailing zeros after a decimal point.
In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the two shorter sides: a squared plus b squared equals c squared. Use it to find an unknown side when two sides are known, and to check whether a triangle is right-angled.
Rounding replaces a number with a simpler approximate value. Identify the rounding digit, look at the next digit, and round up if it is 5 or more, otherwise leave it. Significant figures count all non-zero digits, zeros between significant digits, and trailing zeros after a decimal point.
Fractions, decimals and percentages are three ways to describe the same part of a whole. A fraction becomes a decimal by division, a decimal becomes a percentage by multiplying by 100, and a percentage becomes a fraction by writing it over 100.
Indices (powers) show repeated multiplication. The laws of indices let you multiply and divide powers with the same base by adding or subtracting their indices. Negative indices represent reciprocals and a zero index equals one, provided the base is not zero.
In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the two shorter sides: a squared plus b squared equals c squared. Use it to find an unknown side when two sides are known, and to check whether a triangle is right-angled.
Differentiation measures how a function changes — its rate of change or gradient at a point. The derivative of x to the power n is n times x to the power n minus 1, and it gives the gradient of the tangent to the curve at each point.
Founder and Mathematics Educator at SelexIQ. 28+ years of teaching experience | 20,000+ students taught and guided. Meet Dr. Pankaj Jha →
SelexIQ provides supplementary mathematics enrichment, advanced problem-solving development and preparation for approved mathematics competition programmes. It does not provide or replace school-curriculum instruction.