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Wednesday, December 09, 2015

Multiple Multiplication Algorithms

Students are studying the many ways we are able to multiply large numbers.

We began with studying what happens when we multiply by powers of 10. When we multiply by 10, a number increases by one place on the base-ten place value chart. For example .5 X 10 = 5. Five tenths moves one place to the left to 5. When we divide by powers of ten or multiply by decimal unit fractions like 1/10, 1/100, a number moves to the right by one place for each tenth or power of ten. For example, if we divide by 1 by 10 we get .1, the same is true if we multiply 1 by 1/10.

Next, we studied the area model. This Khan Academy video provides a nice introduction. One that we replicated with the model at the top of the page. After that we reviewed the partial product multiplication algorithm, an algorithm that connects well to mental math strategies and success. We'll practice partial product and the area model with simple math problems, and then we'll move onto the traditional algorithm for multiplication. Step by step we're building students proficiency and understanding with multiplication.