“I just don’t understand estimation. Aren’t you teaching them to find the wrong answer? Why don’t you just teach them to find the exact answer to the problem?”

These were the words that a parent said to one of my colleagues in my building at her parent teacher conference. The parent wasn’t angry, but was firmly questioning. My colleague told me that she was very caught off guard, because the new math series we are using is very “new” to her as well in her thinking. She is a veteran teacher of 22 years, and was taught to carefully calculate when she learned math. She was taught that there was ONE right answer, and that math is about finding that one answer. She has had trouble being fully on board with estimation as well. She came to me because she was looking for what to tell this parent, as it wasn’t the first time she had heard this comment.

Whenever I’ve had this question, I usually present a scenario like this to parents:

Without estimating (either before or after solving), many students make errors without even realizing it. Teaching them to estimate allows them to practice the Standards for Mathematical Practice, especially standard number 1. This standard expects students to make sense of problems and determine if their answer is reasonable. It is about thinking DEEPER, not just quickly or blindly solving problems without knowing if you are on track. Estimation can help us find errors in procedures like the one above.

Teaching children to estimate does not teach them to get the wrong answers, it teaches them to think. Practice it the right way and students will become stronger mathematicians.