Step-by-step explanation:
Basically, It’s important if you want a working program.
computers inly do what you told them to do, so If you wrote something wrong or you wasn't precise enough it might cause a massive damage and cause you to lose a lot of money.
an example from the internet :
On June 4, 1996 an unmanned Ariane rocket exploded just forty seconds after its lift-off.
The rocket cost $7 billion in development and carried a payload worth $500 million. However it never made it to orbit. An investigation revealed that the cause of the failure was a software error in the inertial reference system.
Specifically a 64 bit floating point number relating to the horizontal velocity of the rocket with respect to the platform was converted to a 16 bit signed integer. The number was larger than 32,767, the largest integer storeable in a 16 bit signed integer, and thus the conversion failed.
Over $7 billion can go down the drain in a matter of minutes if not seconds. That is why it is important to be accurate in computer programming. Luckily it was an unmanned flight.