The base of an iceberg is $7 \mathrm{km}$ below sea level. The top is $10 \mathrm{km}$ above the base. How high above sea level is the top of the iceberg $?$

Find the value of the following:

$\left|-3\right|+0$

Find the value of the following.

$\left|-13\right|+0$

Find the value of the following.

$12+\left|-8\right|$

Find the value of the following.

$\left|-16\right|-12$

Find the value of the following.

$\left|-\left|-10\right|\right|$

Find the value of the following.

$\left|-12\right|-12$

Subtract:

$-2459$ from $5128$

Subtract:

$-1040$ from $-687$