The Moon goes round the Earth in a nearly circular orbit of radius 3.84 × 10⁸ m, once every 27.3…

Step 1. Period. $T = 27.3 \times 86\,400\ \text{s} = 2.36 \times 10^{6}\ \text{s}$.

Step 2. Speed. $v = \dfrac{2\pi \times 3.84 \times 10^{8}\ \text{m}}{2.36 \times 10^{6}\ \text{s}} = 1.02 \times 10^{3}\ \text{m/s}$, about $1\ \text{km}$ every second.

Step 3. One day. $1.02\ \text{km/s} \times 86\,400\ \text{s} = 8.84 \times 10^4\ \text{km}$.

Step 4. Angle each day. $\dfrac{360^\circ}{27.3} = 13.2^\circ$.