Question

Find the number of digits after decimal in $\text{Antilog}(-4.8779)$.

Answer 1

Let $y=\text{Antilog}(-4.8779)$

$\log y=-4.8779\log y=-5+5-4.8779\log y=-5+.1221y=\text{Antilog}\left(\stackrel{\_}{5}0.1221\right)$

Now mantissa is $0.1221$

Value corresponding to $0.12$ in $2^{nd}$ column is $864$.

Now main difference value corresponding $0.12$ in $1$ is $0$.

This added to the previous number $=864+0=864$.

Characteristic of $\log x$ is $5$, so there will be four zeroes after decimal.

$\therefore \text{Antilog}(-4.8779)=0.0000864$

Clearly there are $7$ digits after decimal.

So, answer is $7$.