Please share your thoughts about how to address this potential pitfall when teaching this topic.
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Shametria,
ReplyDeleteI LOVED reading through your "Confessions" series! All of them are so spot on and so funny! I strive to teach for understanding, but often have to start from scratch developing my own materials to target the deeper understanding versus just teaching the kids to memorize a trick like "multiply the digits and add zeros." How do you go about targeting deeper understanding of this specific skill? We are just starting to learn to multiply larger numbers with the rectangular array/area model and understanding how to multiply multiples of 10 is so important with this method.
Thanks!
Tammy
tarheelstateteacher.com
Hi Tammy! Thanks for the feedback! I am so glad you found the series useful. I'm familiar with some of those multiplication shortcuts, but students will make the connections on their own given the opportunity. One way to help develop the skill is to list several multiplication problems with zeros, like 72 x 1, 72 x 10, 72 x 100, 72 x 1000, 72 x 10000, etc. Then have students record the products with a calculator. Once all of the products have been recorded, students can look for patterns and make conjectures. You can then extend the conjectures to problems like 72 x 20, 72 x 200, or 72 x .10, 72 x .01 and have students test their hypotheses. This will help make the connection between the size of the number and the digits we use to represent it. Great question! Thanks!
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