“Why are we learning this?”
Have you ever heard this from your students? If you teach math, I’d be surprised if you haven’t. It can be challenging to create a math lesson that students can see the relevance in and that uses/teaches skills they need to know.
But it is possible. In fact, I created one just for Math Geek Mama Readers. Help kids learn and understand math in a real world context with this add and subtract decimals lesson.
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The Best Elements in a Math Lesson
The best math lessons introduce a problem and let students figure out how to solve it themselves. The problem should be interesting to them and relevant to their life. Oh, and there are multiple right answers.
And since I am a homeschooling mom, the lesson needs to span grade and ability levels.
What is the topic? You might ask.
Adding and subtracting decimals. Wait…that sounds boring. Not something I would enjoying teaching or learning.
Let’s try again. The subject is, What’s for lunch?
That’s better. Who doesn’t care about lunch? Especially boys. Especially middle school boys.
What Exactly Will Students Learn?
Since this problem has multiple solutions and multiple ways of solving it, it’s difficult to write an exhaustive list on what students would learn. But you can be sure they will learn:
- Adding money (decimals)
- Subtracting money (although technically they could solve the problem without subtracting)
Plus, other skills like problem solving, making decisions, and defending their answers.
Did I mention you wouldn’t have to do any work? This is a print and go activity with 4 levels to choose from.
The best part? You probably won’t hear “Why are we learning this?” from this activity. 🙂
Included in the Add and Subtract Decimals Lesson:
This download includes everything you need to explore adding and subtracting decimals in context.
- Teaching tips with variations and extensions
- 4 different lunch menus
- A budget answer sheet
Depending on the age or abilities of your kids, you may also want to give them play money to use to help them think through and solve the problem.
Introducing the Lesson:
A fun little book that would go along perfectly with this lesson is The Lunch Line by Karen Nagel. This early reader could serve as an introduction to the lesson, even if you’re teaching older kids. (They like to be read to, too!)
This is the story of Kim who forgets her lunch and must purchase lunch in the cafeteria with only 2 quarters and 5 dimes.
As you read, ask students questions to get them thinking about how to make selections within the budget, how to find the total cost of various choices, etc.
Then give them the What’s for Lunch challenge, and see what kinds of choices they make for themselves!
What’s for Lunch Open-Ended Challenge:
Explain to your kids that they will each have $20 to purchase their lunches for the week. In order to ensure they have enough money to eat everyday, they need to create a budget. They get to choose whatever they’d like each day, but they can’t spend more than $20 for the entire week.
You will then give them a printed menu and a budget worksheet. There are 4 different menus, which increase in difficulty so you can use this open-ended math lesson with kids of various ages and abilities.
If you’re a classroom teacher, this makes differentiating a breeze. Your students don’t even have to know they have different menus!
Or if you’re a homeschool mom, turn this into a family math project, allowing younger kids to choose from the more simply-priced menu, while older kids use the more challenging menu.
Discussing the Math and Strategies:
Once all kids have created their budget, discuss what problems they faced, how they made their selections, and any changes they made.
Allow them to share their strategies for sticking to the budget, as well as their strategies for adding and subtracting the money.
You could then move to a more formal lesson on adding and subtracting decimals to help them solidify their generalizations.
You could also create follow up problems by making your own choices and asking them how much you spent or how much under budget you were.
Adding and Subtracting Decimals Lesson Extensions and Variations:
- For younger kids, remove the budget aspect, and just allow them to make lunch choices and determine the total cost for each day or for the week
- Complete the lesson again, telling kids they get to keep any money they have leftover at the end of the week and see how their budget changes (assuming they must make choices–no skipping lunch allowed!)
- Require older kids to factor tax into the cost and remake their budget
Danielle is a homeschooling mamma of 5. She is committed to making life with young children easier and sharing her passion for math. If you would like to learn more about teaching math to multiple age groups visit Blessedly Busy or follow her on: Facebook, Instagram, Pinterest or Twitter.
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