When you write an equation, it tells you, that you know what the math problem is and your steps of solving. For example if the math problem was that:
Trina invited 9 girls and 10 boys to her birthday. 2 girls didn't come and 1 boy didn't come. What is the total amount of people that came to Trina's birthday party.
It makes everything clear from a mathematical point , much easier to solve the question in equation form than trying to figure it out from a long word problem
