I love "real life math" lessons. There is a facebook meme going around that talks about how school never taught you to balance a cheque book, pay bills, interest on credit cards, etc. etc. but they were so glad they knew Pythagoras theorem.
Funny, but comes from truth. I think 'real life math' helps students relate more and be more engaged in going through the process. Here are a few examples from Raki's Rad Resources, another great edu-blog I follow. Though most of her resources are for sale on 'TPT' if you don't want to buy them, they are still awesome starting points to create your own.
I have done shopping projects with budgets to teach tax and shopping and the kids loved it....
Grade 2 and 3 students completed a Holiday Shopping Project. They used websites like www.amazon.com to do mock holiday shopping. Each student was assigned $100 and chose 3 different presents to purchase. They then practiced rounding, addition and subtraction while putting together their project sheet.
One student decided to spend half of his money on a video game for his brother because “he’ll share it with me!” It was fun to watch him figure out how to get presents for the rest of his family with the money he had left!
Grade 5 and 6 students completed a Balanced Checkbook Project. The students were randomly assigned to a job card, which dictated their salary and bills. Students had to take their annual salary and figure out how much money they would have to work with each month. Then, they had to balance their checkbook by paying their bills and making a grocery list and estimating a grocery budget. Students also had the option of buying luxury items and even had a “surprise” – some good and some bad.