Mathematics Opinion

A Small But Significant Decimal Point

By David Ginsburg — December 24, 2012 1 min read
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There’s really no such number as “point three seven five.” Yet that’s how a lot of students say .375, and a big reason for this is that’s how a lot of teachers say it--including me until I realized this perpetuated students’ difficulties with decimals.

Eventually I referred to rational decimal numbers correctly (“three-hundred seventy-five thousandths,” for example), and insisted students do so too. And not only did students’ grasp of decimal place value improve, but so did their computational skills. Even better, students became more proficient at a skill many kids struggle with: converting between decimals, fractions, and percents.

So, if your students are having a hard time with decimals, make it a point to stop saying “point,” including when referring to mixed numbers (i.e., go with “and” rather than “point;" example: read 15.03 as “fifteen and three hundredths”).

Image provided by Phillip Martin with permission

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