Dividing Decimals at a Concrete Level: Great Guided Math Lessons
The new Math Common Core states that 5th grade students will
Perform operations with multi-digit whole numbers and with decimals to hundredths.
5.NBT.7. Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
So, we need too make sure our students understand decimals thoroughly. We need to teach it at a concrete, pictorial and THEN abstract level. This is the first post of a series that deals with decimals. Here are some resources to teach dividing decimals at a concrete level.
Happy Mathing,
Dr. Nicki
HI Dr. Nicki,
The students in these videos seem to work with the base ten blocks with ease. How much prior modeling did the teacher have to provide before they could articulate how to divide decimals with the blocks? Would the next step be to have them draw a model of their blocks? When could you provide the students with the procedure of “moving the decimal”? (or is a better question – is it necessary to directly teach the procedure?) Even 5th grade students need concrete models to grapple with the concepts of operations with decimals. Time with manipulatives is so often minimized in the intermediate grades, when this time to explore is absolutely essential. I am looking forward to the other posts.
Thanks for the resources. I know this is off topic, but I am writing curriculum with a team of math coaches for Grade 1 to align with Common Core standards – any suggestions or pitfalls to avoid?
Lisa
July 7, 2011
Hi Lisa,
I so agree that manipulatives are underutilized in the upper elementary grades. It is crucial that we teach at the concrete, pictorial and then abstract level. So, I would definitely introduce this, then have them do the pictorial representations with the decimal squares (see the videos) and finally the standard algorithm of moving the decimal.
In terms of the first grade standards…I’m telling all first grade teachers just to tattoo 10A6 on their forearms… (just kidding)…but really learning those facts and building a repertoire of efficient strategies is crucial.
Happy Mathing,
Dr Nicki
drnickinewton
July 19, 2011