Math, asked by quickest, 1 year ago

Tips and tricks to find square and square roots of Two or three digit number, explain it properly.

Answers

Answered by Anonymous
8

Ok I know some tricks of two digit numbers:

First trick

Square of numbers between 80 and 103:

Above 100

103²=10609

  • 103+3=106
  • 3²=09
  • Combine them 103²=10609

106²=11236

  • 106+6=112
  • 6²=36
  • Combine again

Below 100

97²=9409

  • 100-97=3
  • 97-3=94
  • 3²=09
  • Combine

95²=9025

  • 100-95=5
  • 95-5-90
  • 5²=25
  • Combine

Second trick

ending with 5 within 100

Suppose 65²=3025

  • 6*(6-1)=6*5=30
  • 30 and 5² =25
  • Combine

95²=9025

  • 9*10=90
  • 5²=25
  • Combine

I knew many other tricks.

Just forgot them now.

If I remember I will surely help you again.

Hope it helps




Answered by Anonymous
7
Hlo mate :-

Solution :-

● There are some tricks :-

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☆ First add the last digit (2) to the number itself: 32 + 2 = 34.

■ Multiply the sum by the first digit: 34 × 3 = 102. 

■Square the last digit: 2² = 4.Append that square to the product just computed: 1024.

■ If the square is a 2-digit number, append its last digit and carry the first digit to the last digit of the product.

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●Why does this work?

Let the number be N = 10a + b.

(10a + b)²= 100a² + 20ab + b² = 10a(10a + 2b) + b² = 10a(10a + b + b) + b² = 10a(N + b) + b².

So, to compute the square of N = 10a + b, first find N + b. Then multiply that by the first digit a to get a(N + b). Square the second digit to get b². "Appending b²" mean multiplying a(N + b) by 10 and adding b².

In fact the method is not restricted to 2-digit numbers. a may have 2 or more digits as well. The calculations become more complex of course.

Find 215². 215 + 5 = 220. 220 × 21 = 4400 + 220 = 4620. 5² = 25. 4620·10 + 25 = 46225

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☆ ☆ ☆ Hop It's helpful ☆ ☆ ☆
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