# Maths Formulas for Class 7

Most of us start disliking maths at some point or the other due to its huge collection of Formulas. But if you understand the logic behind them you can solve the complex problems too quickly. Have a glance at the Maths Formulas for Class 7 and start your practice right away. Make an effort and try to practice Class 7 Maths Formulas on a regular basis so that you can apply them whenever you want.

## Class 7 Maths Formulas List

If you have any doubts regarding a certain concept of your Class 7 maths clear them by accessing our Maths Formulas. Avail help from the Platform Onlinecalculator.guru and learn formulas of various concepts of Math. Quickly revise the concepts by making the most out of the 7th Class Maths Formula Sheet and Tables. We have everything covered right from basic level to advanced level concepts in our Math Formulae of Class 7.

 Integers Formulas 1) a – b = a + additive inverse of b = a + (– b) 2) a – (– b) = a + additive inverse of (– b) = a + b 3) a + (b + c) = (a + b) + c 4) a × (– b) = (– a) × b = – (a × b) 5) (– a) × (– b) = a × b 6) (a × b) × c = a × (b × c) 7) a × (b + c) = a × b + a × c 8) a × (b – c) = a × b – a × c 9) a ÷ (–b) = (– a) ÷ b where b ≠ 0 10) (– a) ÷ (– b) = a ÷ b where b ≠ 0 11) a ÷ 0 is not defined & a ÷ 1 = a Fractions and Decimals 1) $$\frac{product \,of \,numerators}{Product \,of \,denominators}$$ . For example, $$\frac{4}{5}\times \frac{3}{7}= \frac{4\times3}{5\times7}=\frac{12}{35}$$2) To multiply a decimal number by 10, 100 or 1000, we move the decimal point in the number to the right by as many places as there are zeros over 1. Thus 0.69 × 10 = 6.9, 0.69 × 100 = 69, 0.69 × 1000 = 690 and for dimple decimal numbers see the example – 0.6 × 0.9 = 0.54 3) Division of a decimal number – To divide a decimal number by a whole number, we first divide them as whole numbers. Then place the decimal point in the quotient as in the decimal number. example 12.4 ÷ 4 = 3.1 Data Handling The Average or Arithmetic Mean or Mean = $$\frac{sum \,of \, observations}{number \,of \,observations}$$ Simple Equations An equation is a condition on a variable such that two expressions in the variable should have equal value.Example: 5x + 6 = 26, the LHS and RHS must be balanced therefore to balance the equation the value of x should be 4.The above equation can be solved as> 5x = 26 – 6> 5x = 20> x = $$\frac{20}{5}$$> x = 4 Lines and Angles Two complementary angles: Measures add up to 90° Two supplementary angles: Measures add up to 180° Two adjacent angles: Have a common vertex and a common arm but no common interior. Linear pair: Adjacent and supplementary The Triangle and its Properties For a triangle ABC: Sides: AB, BC, CA Angles: ∠BAC, ∠ABC, ∠BCA Vertices: A, B, C For a right-angled triangle QPR, right angles at P:Pythagoras property $$(QR)^{2}=(PQ)^{2}+(PR)^{2}$$ “In a right-angled triangle, the square on the hypotenuse = sum of the squares on the legs “ Comparing Quantities Simple Interest $$SI=\frac{P\times R\times T}{100}$$Where P=Principal, T= Time in years, R=Rate of interest per annumRate $$R=\frac{SI\times 100}{P\times T}$$ Principal $$P=\frac{SI\times 100}{R\times T}$$ Time $$T=\frac{SI\times 100}{P\times R}$$ Discount = MP-SPPrincipal = Amount – Simple InterestIf the Rate of Discount is given, $$Discount=\frac{Past\, Rate \, of \, discount}{100}$$ Perimeter and Area Perimeter of Square: 4a where a is the side of the squarePerimeter of Rectangle: 2(l+b) units, where l is length and b is the breadth Area of Circle:  $$\pi r^2$$ where r is the radiusArea of Rectangle: lb where l = length and b is the breadthTotal Surface Area (TSA) for Cube: 6a2 TSA of cuboid: 2(lb+bh+hl) Algebraic Expressions $$(a+b)^2=a^2+2ab+b^2$$$$(a-b)^2=a^2-2ab+b^2$$$$a^2-b^2=(a+b)(a-b)$$$$(x+a)(x+b)=x^2+x(a+b)+(ab)$$ Exponents and Powers pm x pn = pm+n{pm}⁄{pn} = pm-n(pm)n = pmnp-m = 1/pmp1 = pP0 = 1