Ayesha had saved ₱500. She bought a gift for a friend worth ₱220. She received ₱100 from her brother but spent ₱155 for her school project. She saw a nice blouse worth ₱250. Does she have enough money to buy the blouse?

Claim:
What is the best mathematical concept to use in solving the problem? The best mathematical concept to use in solving the problem is _________.

Evidence:
What is your solution to the problem?

Reason:
Why is such mathematical concept the best to use in solving the problem? Explain how you came up with your answer.