Roots Problem

[kaushikkumar1987]

Hi,

Can anyone please explain the below problem in detail. Thanks!

Q. Estimate root(60) to the nearest tenth.

What I did here is I found out that the value of rt(60) actually lies between 7 and 8. Its also true that it is more closer to 8 obviously than 7. So, I actually squared 7.5 to see its value. But what is the fastest way to find the value in 'nearest tenth'.

Thanks,
Kaushik K

[Anurag@Gurome]

Estimate root(60) to the nearest tenth.
...
what is the fastest way to find the value in 'nearest tenth'

General Process:
1. Multiply the number with 10² = 100
2. Determine the square root of the product to unit's place
3. Place the decimal between the unit's place and ten's place
4. You have the result

In this case determine the square root of 6000 to units place. Which is between 77 and 78. Hence, the value of square root of 60 to the tenth place is 7.7

Remember some square roots: Remember the square roots of single digit primes. It helps in many situations. In fact the values of √2, √3, and √5 to the thousandth place are enough.

Here, √60 = √(4*3*5) = (√4)*(√3)*(√5) = 2*(1.732)*(2.236) ≈ 7.74

[casperkamal]

Kaushik, would be nice if you mention the answer choices also. I think we can also narrow down the answer by eliminating the choice also