Multiplying 75, 375, 625 and 875

For multiplication that involve 75, 375, 625 and 875, we can convert them into the fraction form to facilitate the calculation process. Below are a few examples of how this is done.

Example 1:
152 x 75 = ?
Answer:
$$\begin{array}{l}152\times 75\\ =152\times \frac{3}{4}\times 100\\ =38\times 3\times 100\\ =11400\end{array}$$

Example 2:
209 x 75 = ?
Answer:
$$\begin{array}{l}209\times 75\\ =(208+1)\times 75\\ =208\times \frac{3}{4}\times 100+75\\ =52\times 3\times 100+75\\ =15675\end{array}$$

Example 3:
744 x 375 = ?
Answer:
$$\begin{array}{l}744\times 375\\ =744\times \frac{3}{8}\times 1000\\ =93\times 3\times 1000\\ =279000\end{array}$$

Example 4:
539 x 375 = ?
Answer:
$$\begin{array}{l}539\times 375\\ =(536+3)\times 375\\ =536\times \frac{3}{8}\times 1000+3\times 375\\ =67\times 3\times 1000+1125\\ =201000+1125=202125\end{array}$$

Example 5:
344 x 625 = ?
Answer:
$$\begin{array}{l}344\times 625\hfill \\ =344\times \frac{5}{8}\times 1000\hfill \\ =43\times 5\times 1000\hfill \\ =215000\hfill \end{array}$$

Example 6:
4168 x 875 =
Answer:
$$\begin{array}{l}4168\times 875\\ =4168\times \frac{7}{8}\times 1000\\ =521\times 7\times 1000\\ =3647000\end{array}$$