Math activity
Price Comparison Challenge
At the grocery store, look at two apples and find which one costs less. Practice noticing that things have prices and prices are not all the same.
Materials and setup
- grocery flyer or store visit
- paper
- pencil
- calculator (upper-elem)
How this changes by age
Pre-K (ages 3–4)
At the grocery store, look at two apples and find which one costs less. Practice noticing that things have prices and prices are not all the same.
Steps
- At the store (or with a flyer), find the apples. Point to two different kinds.
- Look at the price tags together. The parent reads each price out loud.
- Ask: 'Which one costs less money?' Help your child point to the smaller number.
- Pick the cheaper apple to put in the cart and say why: 'This one costs less!'
- Try it once more with bananas or oranges.
- Tell a grown-up one thing that surprised you.
Learning objectives
- Notice that food has prices written on tags
- Compare two prices and pick the smaller one with help
- Build basic awareness of cost
Kindergarten (ages 5–6)
Pick two boxes of cereal. Figure out which one costs less and which one is bigger. Decide which is the better deal in plain words.
Steps
- In the cereal aisle (or with a flyer), pick any two boxes of cereal that look similar.
- Read the price of each one out loud. Which one costs less?
- Look at the size of each box. Which one is bigger?
- Talk about it: sometimes the cheaper box is smaller. Is the cheaper one still a better deal if it has way less cereal?
- Pick the box you think is the best deal and say why in your own words.
- Tell a grown-up one thing that surprised you.
Learning objectives
- Compare two prices and two sizes
- Begin reasoning about value, not just price
- Explain a choice in simple words
Early elementary (ages 6–8)
Compare three brands of the same item. Calculate cost per ounce (or per cracker) and decide which is actually the best deal — then think about whether 'cheapest' is always 'best.'
Steps
- Pick one product (like crackers). Find 3 different brands of it.
- Write down the price and the size in ounces (or count of crackers) for each one.
- For each brand, divide price by size to get cost per ounce (or per cracker). Show the division.
- Make a small chart: Brand, Price, Size, Cost per Unit. Circle the cheapest per unit.
- Now think: does the cheapest one always win? Does taste matter? Brand trust? Quality? Write 2-3 sentences about which one you would actually buy and why.
- Stretch: try the same comparison with a snack you actually like, then taste-test at home.
- In one sentence, tell a parent or sibling what surprised you today.
Learning objectives
- Calculate cost per unit using division with decimals
- Compare three options using a single fair measure
- Reason about value beyond price alone
Upper elementary (ages 8–10)
Calculate unit price for 5 grocery items. Compare brand-name vs store-brand for each, then write a 3-sentence argument about when each one is actually worth it.
Steps
- Pick 5 different grocery items (cereal, pasta, peanut butter, juice, anything).
- For each item, find one brand-name version and one store-brand version. Record the price and the size.
- Calculate unit price for each: price divided by size. Use a calculator. Round to the nearest cent.
- Make a table with columns: Item, Brand Name $/unit, Store Brand $/unit, Difference, % savings on store brand.
- Calculate total cost if you bought all 5 items at brand-name prices vs all 5 at store-brand prices. How much would a family save in a year if they shopped store-brand once a week?
- Write a 3-sentence argument: 'Brand-name is worth the extra cost when ___; store-brand is the smarter choice when ___; my personal rule is ___.' Use evidence from your table.
- In one sentence, tell a parent or sibling what surprised you today.
Learning objectives
- Calculate unit prices using decimal division
- Compute percent savings between two prices
- Make a written, evidence-based consumer argument
Safety and evidence note
Read the full activity before beginning. An adult should supervise tools, heat, food, outdoor work, movement, and experiments as appropriate. Completion records that the activity was done; the child’s explanation, work sample, photo, or demonstration is stronger evidence of learning than a completion check alone.
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