Algebra
Chapter 2 from PECTAA Class 7 math.
There is more than one way to understand this. If you have only been taught one, you have been taught less than you deserve.
There is more than one way to understand this. If you have only been taught one, you have been taught less than you deserve.
Algebra is arithmetic with one number missing, replaced by a letter. The letter is usually x. The job is to find what number x must be so the equation holds true. The whole subject sounds harder than it is, because the rules are the same rules of addition, subtraction, multiplication, and division you already know.
Real life situation. You go to the petrol pump with 2000 rupees. Petrol costs 290 rupees per litre. You want to know how many litres you can buy. Let x be the number of litres. The equation is 290 times x equals 2000. Divide both sides by 290 and x equals about 6.9 litres. The pump fills 6.9 litres for your 2000 rupees.
The big rule of algebra. Whatever you do to one side of the equation, you must do to the other side. Add 5 to the left, add 5 to the right. Divide left by 7, divide right by 7. The equals sign is a balance. If you put weight on one side and not the other, the balance tips and the equation breaks.
Today's habit. Find one situation in your day that has an unknown. Maybe how many bus rides you can afford this week, or how many hours of study fit before iftar, or how many friends can sit on a charpai. Write it as an equation with x. Solve. Compare with reality.
Estimated time: 16 min