Question

What could be the possible once's digit of the square root of 256

Answer 1

Answer:

16

Step-by-step explanation:

10^2 = 100 and 20^2 = 400

so the square root of 256 lies between 10 and 20. And the unit digit in 256 is 6.

4^2 = 16 and 6^2 = 36 so lets try 14 and 16 as possible answers.

14^2 = 196 no too small

16^2 = 256 This works !!!!!!

Also raise 10 to the power (1/2)*log(256) if you have access to log values.

While in university during the late 1950’s we used 13 place log tables when we needed more accuracy than was possible with a slide rule. Bulky hand held calculators (made in Mexico for $150) became available in the mid to late 60’s. They had +, - , x , /, the square root function and maybe a memory.

Log 256 = 2.408239965

1/2 log 256 = 1.204119983

11^1.204119983 = 16