“YES! Esti-mystery! You can play too. You have to guess how many there are. Then you get 4 clues and then you find out.”
This week, 4th grade mathematicians were excited to share a warm-up routine that challenges players to look at a photo, form an estimation range, select a single estimate, then refine their answer with new information. The photo Wednesday was of tiny globe keychains filling a tall drinking glass—how many are there? Students cautioned me not to make my range too big (or else it would be like cheating).
After each writing our first estimate and a range we thought was probable, we learned clues like the answer is a number in this pattern: 51,54,57,60…” And, the answer is an odd number. With each of the four new clues, players update their estimate using the new information in their math journals, but without erasing any prior thinking. As one student noted, “I picked 63 because it’s kind of in between there.”
After the last clue, we listed around the room possible final answers we had selected, then students were asked to name if any of these final guesses was not a possible solution. Their teacher reminded them, “If you want to eliminate an answer, you have to say why.”
One student noted, “Only two of those work with all the rules. It can’t be 79 because there’s 78 there [if you follow the pattern] but you’d have to add 1 to get 79, not three.” Another summarized a divisibility rule they had discovered the week prior about multiples of three.
Cheers and “awws” resounded as we discovered the answer.
As they study factors and multiples, daily warm-ups prime students’ math thinking and engage them in authentic practice of many of the Math Process Skills they will build throughout their JK-12 trajectory. Skills like critiquing your own and others’ reasoning, making your thinking visible, and looking for patterns all underpin this game, and build a mindset that math is for everyone, is fun, and can be accessed by reasoning skills which we all can practice!