When Celsius Scale Convert into Kelvin Scale, we add 273? why?

We divided the Celsius scale equally 100 pan from 0 – 100. On the other hand, Kelvin scale is divided equally 100 part from 273 – 373. The temperature of any substance become 0°C, in Kelvin scale the temperature will be 273k. So the difference between Kelvin and Celsius scale is 273.