On the shopping list, one item has a "?" price tag.
Below it you see the total amount that was paid.
Subtract the known prices from the amount paid, and the missing price is left over.
Example
- 5
For parents
What does this exercise practice?
The price puzzle practices equation thinking without letters, using euros instead of balance scales - the child recognizes that the total amount paid is the sum of all individual prices and works backward to find the missing price.
Common pitfalls
If an item with the "?" tag appears more than once (e.g. two apples), its price only counts twice after working it out. Overlooking an item bought more than once means subtracting too little from the amount paid.
How to practice at home
On the next shopping trip, look at the receipt together and cover up one item - how much did it probably cost if you know the rest?
Related: Shopping, Balance puzzle