Exploring the Hundred Chart with Mystery Number Skype

We have used Skype extensively in kindergarten for a number of years, but we have never participated in Mystery Number Skype. After attending Kathy Cassidy's presentation at Awakening Possibilities last month, I was inspired to put this idea into practice with my colleague Leah Obach and her grade 1 class.

How does Mystery Number Skype work? Well it's beyond simple actually! Each class chooses a mystery number based on whatever criteria you have set. We are currently focusing on numbers 1-100 at the moment. The classes then connect on Skype. One class goes first, and asks the other class yes/no questions to narrow down what the mystery number could be. Once the first class guesses the number correctly, the other class takes their turn. McGraw-Hill's Monster Squeeze app is a great way for students to increase their understanding of how to narrow down a range of numbers.

We share the screen and use the interactive hundred grid in SMART Notebook to give both classes a visual. As it is narrowed down, students flip over the numbers. My students each have their own device to use, so we are using the Hands On Math Hundred Chart app. Learn more about how the app works in this tutorial video. Students were super engaged as they asked questions and coloured in numbers on their device during Mystery Skype.

 We have done mini-lessons on "smart" questions to ask, and these are the questions we are hearing from our students during Mystery Number Skype:
Is it higher than __?
Is it lower than __?
Is it between __ and __?
Is it in the forties, fifties, sixties, etc.?
Does it end with a __?

After three days of Mystery Number Skype, Leah and I have decided that a few new mini-lessons are needed to stretch the students' thinking and question-asking abilities. Topics we plan to address in the next week include odd/even numbers, skip counting patterns, and the difference between "teen" and "ty" (decade) numbers. Leah's Grade 1 class already demonstrates a good understanding of teen/ty numbers, so her students may actually teach a mini-lesson to my students.

Today our classes competed to see who could solve the mystery number asking the fewest number of questions. We tallied each question on the SMART Board as they were asked, which definitely increased student motivation to ask "smart" questions. This provided another role for students to play during Mystery Number Skype as well as some great skip counting practice.

After only 3 days of Mystery Number Skype, I am really impressed by the growth I've seen in my senior kindergarten students' abilities to use and ask reasonable questions about the hundred chart. Their excitement and engagement is through the roof as well. If you're looking for a fun way to connect with another class and develop 21st century skills in your students while boosting numeracy skills, this is it!