Keeping the significant figures in view, the sum of the physical quantities $52.01 \ m$, $153.2 \ m$, and $0.123 \ m$ is: (in $m$)

Each side of a cube is measured to be $7.203 \; m$. What are the total surface area and the volume of the cube to appropriate significant figures?

$A$ person measures the mass of $3$ different particles as $435.42 \ g$,$226.3 \ g$,and $0.125 \ g$. According to the rules for arithmetic operations with significant figures,the sum of the masses of the $3$ particles will be: (in $g$)

An object of mass $m = 3.513 \ kg$ moves along the $x$-axis with a velocity of $5.00 \ ms^{-1}$. The magnitude of its momentum can be recorded as $...... \ kg \ ms^{-1}$.

If $L = 2.331 \ cm$ and $B = 2.1 \ cm$,then $L + B =$ (in $cm$)

The mass of a box measured by a grocer's balance is $2.30 \ kg$. Two gold pieces of masses $20.15 \ g$ and $20.17 \ g$ are added to the box. What is
$(a)$ the total mass of the box,
$(b)$ the difference in the masses of the pieces to correct significant figures?