Thank you Mother and Father for all of those diapers  Which is a better deal, cloth or disposable diapers? How much did you cost your parents in diapers? In the future how much could your kid's diapers cost? Help students realize all that mom and dad went through in buying and changing diapers.
Students will compare the cost of buying disposable versus cloth diapers. They estimate how much they cost their parents in diapers and consider how much they will spend on diapers when they have a baby. This is a great math activity for Father’s Day or during the study of linear equations and introduction to systems of equations.
There is quite a bit of scaffolding built into the activity for students who might have limited experience with linear relationships and equation writing. Depending on the experience of your students you might reduce the amount of work in the tables or omit some of the questions in this part of the lesson.
CCSS: 6.EE.9, 7.EE.4, 8.F.2, 8.F.4, 8.EE.8, HS.FIF.8.B, HS.FLE.2, HS.FLE.5, MP7, MP8
Or check out:
Father's Day Blueberry Muffins is a short activity that asks students to change the amounts in a blueberry muffin recipe to multiples of and fractions of a ¼ cup measuring cup (multiplication and division with unit fractions). CCSS: 4.NF.4, 4th, 5.NF.7, 5th, 6.NS.1, 6th, 7.NS.2
Or just concentrate on Chocolate ...

 Big Snickers bar  3act task; How much bigger than a regular Snickers bar is that?
 World record Snickers Bar  Recently the Texas Mars factory workers created the World's largest Snickers Bar. Students explore similarity, crosssections and number of servings (equivalent number of minisnickers bars).
 Shrinking Toblerone  Two sizes of Toblerone bars are now configured differently. How much did they lop off? How much did the price per gram of chocolate change? Is the price per gram still the same, if not how might you adjust the price of the products to make it fair? How much could you buy for $1.00? Could you have designed it better?
 Giant Chocolate bunnies  What can you deduce about the bunnies (pictured in this activity) from the descriptions given ... solid? hollow? cost per pound? cost per height?
 The size of chocolates  Students approximate the volume  Mean radius method and the counting squares.
 Chocolate milk and mixture problems  changing percent mixtures through a fun class day that ends with a yummy treat.
 Chocolate raspberry heart cake  Students calculate base area or volume of cakes made from 2 cake pan sizes and observe how the volume of the cake changes with the increased pan size. This is an activity intended to demonstrate that the volume increase is not linear. Volume expansion would be cubed if all dimensions of the cake were enlarged but in this case (since we didn't increase cake depth) only two dimensions are enlarged.
 Holiday candy sales  Translate a pie chart of information on candy sales to actual dollars spent. Ponder the amount of money that is spent on various holidays for candy.
 Too early in the day for so many choices  Calculate the number of combinations possible in a story of buying a warm drink when you are still sleepy and there is too much to decide.