Math teachers of older students sometimes struggle to get students to explain their thinking with evidence. It's hard to get kids in the habit of talking about how they are thinking about a problem when they've had many years of instruction that focused on getting the "right answer." That's why educators are now trying to get students in the habit of explaining their thinking at a young age. The Teaching Channel captured kindergarten and first grade teachers pushing students to give evidence for their answers in situations where there are several ways to think about a problem.
Pattern recognition is a fundamental part of mathematics and kindergarteners are not too young to notice, compare and describe simple patterns. In this video, kindergarten teacher Donella Oleston describes how she had to back up and explain to these young learners what it means to "explain your thinking," because at first students would only answer, "My brain told me so." With practice, she says students have gotten to deeper levels of noticing, moving past the obvious and picking out more abstract similarities and differences between two pattern sets.