Useful knowledge for calculation

Prefix

Name Symbol $10^n$
kilo k $10^3$
hecto h $10^2$
deca da $10^1$
    $10^0$
deci d $10^{-1}$
centi c $10^{-2}$

Pressure

\begin{align}
1 \mathrm{\,Pa}&=1 \mathrm{\,N/m^2}\\
\text{Atmospheric pressure}&=1013.25 \mathrm{\,hPa}= 0.101325\mathrm{\,MPa}
\end{align}

Others

Density of water:

$$\rho \sim 1 \mathrm{\,g/cm^3}=1000 \mathrm{\,kg/m^3}$$

Water pressure:

Let gravitational acceleration be $g\sim 10 \mathrm{\,m/s^2}$.
According to above calculation, water pressure at a depth of 1m is
$$10^4 \mathrm{\,(kg\cdot m/s^2)/m^2}=10^4\mathrm{\,N/m^2}=10\mathrm{\,k Pa}.$$