You can find math everywhere - even when you are at the grocery store. Whether you and your child are at a large grocery store or small market, you can help your child engage in math in a way that is fun and educational.
We consulted with Marc Husband, an elementary school teacher and teacher educator, to create these tips on how to find math everywhere at the grocery store.
Geometry, Multiplicative Thinking and Data Management
As you make your way around the grocery store, you’ll see different rows and columns of 3-dimensional figures, from rectangular prisms in the cereal aisle to cylinders in the canned soup section. Look around and ask your child questions.
- Rectangular prisms and cylinders. Can your child find rectanglar prisms (cereal boxes, pancake mix) and cylinders (cans of soup or tuna)? What kinds of products or foods are boxed? What kinds of products are in cans? What other shapes can you see in each can or box?
- Rows, columns and multiplicative thinking. Looking at cans of tuna or soup on a shelf, can you describe how many rows are there? Can you describe the number of cans in each column? How many cans do you estimate? Can your child estimate the number of cans of tuna or soup on a shelf by multiplying the number of cans in a row and in a column?
- "What if?" What if you needed to stock your kitchen with soup and you could only spend $10. One brand of soup sells three for $2 and a different brand sells for 50 cents each. Which is the better value? How many cans you buy with $10 before taxes?
Measurement, Weight and Estimation
The produce aisle is probably one of the first departments you’ll enter at the grocery store. This is where you’ll find a produce scale - a great math learning tool.
- Weight Measurement. Measure a favourite fruit or vegetable. One apple weights about 200g . If you bought 1 kg of apples, how many apples would you get?
- Estimation. Give your child different types of vegetables or fruit – like onions and potatoes— and compare them with apples. Have your child compare them in his or her hand. Which one is heavier? Which is lighter? Use the produce scale to test the estimate.
- "What if?" If an apple pie or apple crumble recipe calls for 8 cups (2L) of apples, how many apples will you need? What if you wanted to double or halve the recipe?
Money Management, Measurement and Estimation
The grocery store is the perfect place to develop money management skills.
- Bench marks, estimation and money. Estimating the cost of the total price of your grocery cart or basket is a good skill – for both kids and parents. An easy way to estimate is to use benchmarks of $5 or $10 for each item. How many $5 items do you have? How many $10 items do you have? What is the total estimate? For a challenge, set a budget and try to come within the budget.
- Calculating tax. Once you’re finished at the cashier, use the receipt and calculate an estimate for tax. One way to think about calculating the 13% HST in Ontario is use an approximation. The first step is to take the total amount of groceries. Then, calculate 10%. Then, halve this amount (5%). Finally, add the two numbers. This equation won’t be precise, but will be fine to estimate how much you’ll need.
- "What if?" You put your child in charge of making an apple crumble recipe for a potluck, and you have budgeted $20 for the apples. How many apples do you need to buy if each apple weighs around 200g and the recipe calls for 2L? One your child has determined how many apples are needed, ask how much will it cost to buy that many apples? With a $20 budget, do you have enough money?
- Different ways to think about and do math.
- Curriculum - these activities touch on the five strands of the Ontario elementary math curriculum: number sense and numeration, measurement, geometry and spatial sense, patterning and algebra, and data management and probability.
- Math skills like problem solving, reasoning and proving, selecting tools and computational strategies, reflecting, connecting, representing and communicating.
- That math is everywhere, and fun!