💛 Error Analysis Day 71

Error Analysis

Introduction

In becoming a master at being able to use models and strategies to multiply multi digit numbers, it is important that mathematicians are able to find errors in their mathematics. In this lesson, we will look at different strategies in order to look for any errors.  In doing that, the best way to analyze a strategy is to compare the work you would do to solve the problem, then compare.  So, when you see a multiplication problem solved using a rectangular model, solve the problem in the same way, and compare the two.  Do the same with any strategy being used.  By doing this, it will help you find the errors.

 Guided Practice

Rectangular Model Anchor Chart Break each factor into tens and ones. Show the factors broken apart by drawing the lines to divide up your area model. You now have 4 smaller parts of the rectangular area model that you can use the given dimensions to find the partial products of the bigger rectangle. Once you have found each of the products, add them all together to find the final product.Partial Products Anchor Chart (1).jpg

Stop and Jot

In your Notebook: Look at Terrence's work below. He drew an area model. Can you find his error? Explain in your notebook.

50x20= 100 20x7= 140 5x50= 250 5x7= 35

 

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