Many children are confused by decimals. They are convinced 0.48 > 0.6 because 48 is obviously ever so much bigger than 6. Their intuition tells them 0.2 × 0.3 = 0.6 has the clear ring of truth. And they confidently assert that, if you want to multiply a decimal number by 10, all you have to do is add a zero at the end.
What can we do to help our kids understand decimals?
Christopher Danielson (author of Talking Math with Your Kids) will be hosting the Triangleman Decimal Institute, a free, in-depth, online chat for “everyone involved in children’s learning of decimals.” The Institute starts tomorrow, September 30 (sorry for the short notice!), but you can join in the discussion at any time:
Past discussions stay open, so feel free to jump into the course whenever you can. Here is the schedule of “classes”:
Syllabus
[See the introductory post above for how to join. I’ll try to remember to come back and add links as the topics go live.]
Come join us for some or all of the following.
Week 1 (Sept. 30): Decimals before fractions?
Week 2 (Oct. 7): Money and decimals.
Week 3 (Oct. 14): Children’s experiences with partitioning.
Week 4 (Oct. 21): Interlude on the slicing of pizzas.
Week 5 (Oct. 28): Grouping is different from partitioning.
Week 6 (Nov. 4): Decimals and curriculum (Common Core).
Week 7 (Nov. 14): Summary and wrap up.There will be no grades, tests or tuition. Just the love of knowledge and the collective passion of teachers wanting to do their best.
Denise Gaskins' Let's Play Math 