Example 1 - Chapter 6 Class 8 Squares and Square Roots
Last updated at Sept. 11, 2018 by Teachoo
Transcript
Example 1 Find the square of the following numbers without actual multiplication. (i) 39 We know that 39 = 30 + 9 Now, 392 = 39 × 39 = (30 + 9) × (30 + 9) = 30 × (30 + 9) + 9 × (30 + 9) = 30 × 30 + (30 × 9) + (9 × 30) + 9 × 9 = 900 + 270 + 270 + 81 = 1521 Example 1 Find the square of the following numbers without actual multiplication. (ii) 42 We know that 42 = 40 + 2 Now, 422 = 42 × 42 = (40 + 2) × (40 + 2) = 40 × (40 + 2) + 2 × (40 + 2) = 40 × 40 + (40 × 2) + (2 × 40) + 2 × 2 = 1600 + 80 + 80 + 4 = 1764
Chapter 6 Class 8 Squares and Square Roots
Concept wise
- Square numbers
- Properties of square numbers
- Sum of consecutive odd numbers
- Numbers between square numbers
- Pattern Solving
-
Finding square of large numbers
- Pythagorean triplets
- Square root
- Finding Square root through repeated subtraction
- Finding Square root through prime factorisation
- Checking if perfect square by prime factorisation
- Smallest number multiplied to get perfect square
- Smallest number divided to get perfect square
- Smallest square number divisible by numbers
- Finding number of digits in square root (without calculation)
- Finding square root by division method - Integers
- Least number subtracted to get a perfect square
- Least number added to get a perfect square
- Finding square root by division method - Decimals
- Statement Questions
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.