## Why Japanese Multiplication Works

Japanese Multiplication? Chinese Multiplication? Line Multiplication? Whatever it's called, it's only a trick if you simply memorize without meaning Have you ever wondered why Japanese multiplication works? I've heard some call it Chinese multiplication, multiplication from India, Vedic multiplication, stick multiplication, line multiplication and many more. While many might argue as to the origin of this multiplication trick, I’m going to argue that it very well could have originated right here in Ontario, Canada, considering how our Ontario grade 1 to 8 math curriculum suggests we might go about teaching multiplication. But just for the record, I really do have no idea where it came from and nor do I care. I do, however, REALLY ca...

## Donut Delight

Sparking Curiosity to Promote Conceptual Understanding of Multiplication and Division When one of our district math leads, Brennan Jones asked me to brainstorm some ways we could help his staff engage in some professional development around division and incorporate a 3 act math task into the learning, I immediately thought of some contexts where arrays, base ten blocks and area models could be used to help attack this concept. I was thinking about a box of Coca-Cola, jars of peppers and many other ideas prior to settling on the idea of donuts in a box. It was then that I remembered that Graham Fletcher, Mike Wiernicki, YummyMath and others had explored the Krispy Kreme Double Hundred Dozen box of doughnuts in the past (read about i...

## Airplane Problem – Trip to Toronto

From Subitizing and Unitizing to Multiplicative and Algebraic Thinking This 3 act math task was designed specifically to have a very low floor in order to be useful from primary grades and a high ceiling with an opportunity for many extensions so the task can be used in junior and intermediate classrooms. While I believe this task can touch on many different specific expectations at many different grade levels, listed below are just a few possibilities from the Ontario curriculum. Regardless of grade level, I recommend teachers show the task videos and and complete the initial "notice / wonder" to spark curiosity. After the initial task is completed, you may decide that jumping ahead to a grade appropriate extension is worthwh...

## The Progression of Multiplication

Arrays and Area Models to The Standard Algorithm Did you know that the words "array" and "area model" appear in the Grade 1-8 Math Curriculum a combined 22 times? Not only do arrays and area models help to support the development of proportional reasoning when we formally introduce multiplication in primary, but they also help us understand how to develop strategies that lead to building number flexibility and the automaticity of math facts. Arrays and area models should be used as a tool and representation for many big ideas in mathematics including, but not limited to: Multiplication Distributive Property with Whole Numbers Finding Area with Whole Number Dimensions Perfect Squares & Square Roots Multiplying ...

## Are Math Facts “THE” Urgent Student Learning Need?

Or, are they just a piece of a massive, more complex problem? This past Thursday for our MYCI Planning Meeting WSG Dan Meyer, there was quite a bit of discussion surrounding math facts as a student learning need. This is no surprise, as I think we can all agree that this is an area we would like to support our students in. The discussions at each table made it clear to me that we are all passionate about supporting our students in their mathematical journeys. Some of the discussions focused on math facts in general, while others were more specific such as being able to recall multiplication facts or working with fractions. All great discussion with great ideas being carved out along the way. During our time debriefing the session, Justi...