i need the important formulas in maths for class 7
Answers
Proportion Formula Rules:
Addition: ab+cd=ad+bcbd
Subtraction: ab−cd=ad−bcbd
Multiplication:ab=cd, then a*d = b*c
Division : abcd=adbc
Set properties:
Commutative property: A∪B=B∪A A∩B=B∩A
Associative property:(A∪B)∪C=A∪(B∪C) (A∩B)∩C=A∩(B∩C)
Algebraic Expression Expansion:
(a+b)2=a2+2ab+b2
(a−b)2=a2−2ab+b2
a2−b2=(a+b)(a−b)
(x+a)(x+b)=x2+x(a+b)+(ab)
Consumer Math Formulas:
Simple Interest, S.I=PTR100,
Where P=Principal, T= Time in years,R=Rate of interest per annum
Rate,R=100∗S.IP∗T
Principal,P=100∗S.IR∗T
Time,T=100∗S.IR∗P
Discount = MP-SP
Principal = Amount – Simple Interest
If Rate of Discount is given, Discount=PastRateofDiscount100
Time and Speed:
Speed=DistancetravelledTimetaken
NumberofRevolution=DistancetravelledCircumferenceofthewheel
Area Formulas for 2D and 3D Figures:
Circle=pir2 Sq units, where r is the radius
Rectangle= l∗b Sq.units , where l = length and b is breadth
Total Surface Area for Cube = 6a2 sq.units
Total surface Area of cuboid =2(lb+bh+hl) Sq.units
Perimeter Formulas
Square = 4s units, where s is side of square
Rectangle= 2(l+b) units, where l is length and b is breadth
Volume Formulas:
Cube =l3 cu.units
Sphere=43πr3 cu.units,where r is the radius of the sphere.
Cylinder= πr2h cu.units,where r is the radius of the base,h is the height of the cylinder.
Chapters of maths class 7th
Chapter 1 – Integers Formulas.
Chapter 2 – Fractions and Decimals Formulas.
Chapter 3 – Data Handling Formulas.
Chapter 5 – Lines and Angles Formulas.
Chapter 6 – The Triangle and Its Properties Formulas.
Chapter 7 – Congruence of Triangles Formulas.
Chapter 9 – Rational Numbers Formulas.
Go though the last page of each lesson on maths text book the list of points and important formulas are given: