Before starting this post, let me state first that this post is not about my like or dislike for Maths. It is about some Maths topics that I could use in real life. Also Maths was not my favorite subject in school, but it was one subject that I managed to score well by having enough practice.
I feel that my teachers played a part in making some Maths topics applicable to the real life and thus making the lessons more interesting.
When I was in primary school, one of the Maths topics was related to money such as the counting of money, how much change to get from the cashier, and so on. It was very useful and got me to realize that 10 ten-cent coins is of less value than a $10 note. Before that I was naive enough to think that having many coins made me feel richer than having a few big dollar notes. When I went grocery shopping with my mum, I would also try to show off by calculating the cost of the grocery and the change to get from the cashier. Of course the cashier was always correct.
Later when I was in secondary school, l learnt about calculating interests: simple interest and compound interest. I remember my teacher used loans with compound interests to show us how compound interest could snowball to the point that the loan amount became a few times higher than the principal amount even though the interest rate seemed like an innocent 2%. To be frank I really dreaded calculating compound interest for those practice questions.
In college, one of the Maths topics was on probability, combinations, and permutations. The teacher, in his attempt to get us interested in the lesson, told us how probability was relevant to gambling. One of the practice questions was to calculate the probability of getting the various poker hands: royal flush, straight flush, full house, and so on. Once we got the probabilities, it dawned upon us how difficult it is to get a good high-value poker hand. For the interested readers you can find the probabilities of the poker hands on internet as I have forgotten the calculation. The side-effect of that topic was it taught me that the odds of winning in gambling are really low.
Of course there were other Maths topics that were useful and practical in real life such as measurement.