Financial Education is the new feature in the General Education Curriculum of Mathematics 2018 and is focused throughout the curriculum, from elementary to high school. This article would like to clarify the concepts related to financial education and provide pedagogical measures to integrate financial education into teaching Mathematics in high schools. An experiment in teaching exponential functions improved financial literacy for grade 12th students using credit cards shows the realizable and effectiveness of proposed measures. Thereby, students learned about credit cards (credit card statements, credit interest rates, closing balances, and annual fees), how credit cards work, how to calculate credit card debt, make a decision whether to pay via credit card or not, and explain why and how to use a credit card to be safe and avoid risks.