A blog this week asked us to guess the grade level for which this math problem was written:
Kristen has four flowers. She gives some to a friend. Now Kristen has two flowers. How many did Kristen give her friend? Draw pictures to help you solve the problem.
It’s listed as a kindergarten homework problem.
If you teach math, you know this problem includes some of the biggest arithmetic concepts there are and you’re not deceived by the use of small numbers.
- Students need to understand hierarchical inclusion–that 4 includes 2
- They need to understand conservation–that the number of objects remains the same, no matter how they are arranged
- And, they need to understand cardinality, that the name of a number relates to a specific quantity–including the huge idea that “two” isn’t the second object, but a set of two objects. This is a major leap in knowledge, often hindered by memorizing names of numbers. Too often, students learn to count to 30 or 100 but don’t understand the concepts involved.