Explain using an example why you need to multiply when converting from a larger unit to a smaller unit

Okay so let's say I wanted to change 100cm into mm
I would multiply 100 by 10 because there are 10 mm in a cm
so it would be 1000mm
for example :

500cm to mm
= 500*10
=5000 mm

I have included a picture to help!
hope this helps you!

Answer x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​

step-by-step explanation: