Question 1 - Page 136 - ‘Think of a Number’ Tricks - Chapter 6 Class 8 - Algebra Play (Ganita Prakash II)

Transcript

Question 1 - Page 136 How would you change this game to make the final answer 3? What about 5? Our original trick was this To get an answer of 3 Look at step 3 where we added 4 . When we divided by 2 in the next step, that 4 became a 2 . So, if we want to end up with a 3, we need to add 3 × 2 = 6 New Rule: Change "Add 4" to "Add 6". Thus, our trick is now Think of a number: x Double it: 2x Add six: 2x + 6 Divide by 2: (2𝑥 + 6)/2 = x + 3 Subtract the original number you thought of: x + 3 – x = 3 To get an answer of 5 Using the same logic, We add 5 × 2 = 10 New Rule: Change "Add 4" to "Add 10". Thus, our trick is now Think of a number: x Double it: 2x Add ten: 2x + 10 Divide by 2: (2𝑥 + 10)/2 = x + 5 Subtract the original number you thought of: x + 5 – x = 5