Place Value – How Important Is It Really?


Place Value – How Important Is It Really?
It's important to teach students a Conceptual understanding of the role of Place values by Going beyond an Algorithm. 

The little girl sits puzzling over the problem on the page. She’s only in grade two, but the stress of high performance expectations is already in place. Here’s the problem she needs to solve:

500 – 78

The little girl remembers that she needs to cross out the five and make it a four. She also knows that one of the zeros becomes a nine and the other one becomes a ten, but she just can’t remember which is which, and it’s so frustrating! Finally, she has an idea. She tries different values and adds 78 to each of them until she comes up with:

422 + 78 = 500

She writes 422 as the answer and receives that coveted gold star on her paper. No one knows that she doesn’t understand how to complete this type of subtraction with regrouping (or “borrowing,” as it was called in her day).

In working with several primary schools for the last couple of years, I have seen this happening time and time again.

So what is the issue? Hint: It isn’t a faulty memory. It is what happens when a student is taught only an algorithm and is not given any conceptual understanding of the role of place value.

The definition of place value is rather simple. Place value is the position of a number that tells what value it is assigned. Here at Maths Australia we often say place value tells “what kind” or “what value.” This is in contrast to the digits 0-9, which indicate “how many.” For example, in the number 246, the digit 4 indicates there are four (how many) tens (what kind/place value). Despite its simple definition, place value can be a challenging concept for a young child to grasp. Regardless of whether dad is in the kitchen, the living room, or the garage, he is still dad, but if the digit 3 is in different locations (tens or hundreds place, for example), it means something different. In the Math-U-See curriculum place value is first introduced in the Primer level with the fun and relatable illustration of Decimal Street. Each of the houses on Decimal Street represents a separate place value. This is reiterated in the Alpha level and again in Beta.

From the opening story, you saw that place value has some impact on mathematical understanding, but how important is it? According to Sherman, Richardson, and Yard, “Place value is perhaps the most fundamental concept embedded in the elementary and middle school mathematics curriculum.” Place value provides the foundation for regrouping, multiple-digit multiplication, and more in the base-ten (decimal) system, as well as a starting point for the understanding of other base systems. Place value allows your 12-year-old son to understand the difference between the $50 he received for his birthday and the $500 price tag on the tablet he’s saving for. Place value allows the student learning scientific notation to understand why 54,800,000 can be represented as 5.48 X 10. 

“Place value is perhaps the most fundamental concept embedded in the elementary and middle school mathematics curriculum.”

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Studies have shown that place value understanding has a positive correlation with overall mathematics achievement. For the grade 2 student described above, place value would have helped her understand that when she crossed out the 5 in 500, she was really decomposing 1 hundred into 10 tens, of which 1 needed to go to the ones or units place to allow her to subtract, leaving 9 to go to the tens place. There would have been no need to memorize (and forget) an algorithm!

Hopefully you are convinced that place value is important, but does it really matter how it is taught? Research has shown a correlation between using base-ten manipulative representations of numbers (as opposed to one-to-one representations) and understanding of place value. In other words, representing the number 24 with two 10 blocks and four units rather than 24 units correlates with a better understanding of place value. The Math-U-See presentation of place value using Decimal Street and our color-coded pieces for units, tens, and hundreds supports this desired base-ten representation. Additionally, studies have shown that the way numbers are verbalized by English-language speakers may negatively influence the way students think about and represent numbers in comparison to Asian-language speakers. Math-U-See provides some alternate number naming strategies to help bridge this gap and promote better understanding of base ten.

We invite you to watch the video presentation on place value and see how Math-U-See can help your students gain a better understanding of this foundational concept.

References

1. Kouba, V. L., Brown, C. A., Carpenter, T. P., Lindquist, M. M., Silver, E. A., & Swafford, J. O. (1988). Results of the fourth NAEP assessment of mathematics: Number, operations, and word problems. Arithmetic Teacher, 35(8), 14-19.

2. Miura, I. T., & Okamoto, Y. (1989). Comparisons of U.S. and Japanese first graders’ cognitive representation of number and understanding of place value. Journal of Educational Psychology,81(1), 109-114.

3. Miura, I. T., Okamoto, Y., Kim, C. C., Steere, M., & Fayol, M. (1993). Cross-national comparisons: France, Japan, Korea, Sweden, and the United States. Journal of Educational Psychology,85(1), 24-30.

4. Sherman, H. J., Richardson, L. I., & Yard, G. J. (2014). The impact of place value on mathematics. Retrieived January 13, 2017, from http://www.education.com/reference/article/impact-place-value-mathematics/.

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