Hi all,

I was wondering if there would be any reason not to refer to tens as 2-ten zero (instead of just 2-ten) for 20, 3-ten zero for 30, 4-ten zero for 40, etc. My daughter started doing this yesterday when we were looking at numbers and I left it (i.e. I did not correct it or suggest just saying 2-ten), but wanted to get some input on whether there would be a downfall to sticking with her way.

Hmmmm, I can't see a problem with it. I would let my kids do it.

Heather

Hi Ashlee,

The only thing I would foresee is that it is not mathematically correct.
2-ten zero would be written 200.

She needs to understand that 2-ten IS 2 units of tens and that looks like 20.

Place value is always hard for young children, it is very abstract, but with time, and experience, they will not only learn it they will understand it.

Place value is one of the corner stones of understanding mathematics correctly, as in our decimal number system we do not have symbols for numbers above the number 9, so we need place value to help us show numbers that are larger than 9. The more we understand place value the less we need to memorize math facts, and more we can understand how to solve unknown math problem.

So if she felt success in her math, and you knew what she meant, I would not have marked her wrong, but I would know that I need to work with her understanding of place value, and I would then bring it up regularly and point it out more often so she can have more experiences with this concept.

Please let me know if you have any more questions. You can email me directly at Carissa@alabacus.com .

Thank you for giving your child a RightStart in Math,

Carissa
RightStart™ Mathematics by Activities for Learning, Inc.

For program questions: 888.272.3291
To place an order: 888.RS.5.MATH (888.775.6284)
www.RightStartMath.com

Our Mission: To help children understand, apply, and enjoy mathematics

Could you help me understand how it is mathematically incorrect? If 2-ten one is 21, why would 2-ten zero be 200?

Hello Ashlee,

You have raised an excellent question and you are correct, it is not mathematically incorrect, but it is redundant. She need not have the extra zero.

When I called it mathematically incorrect, I was thinking of how the young children who are learning this way will write the place value 234 as 200304, and it takes some time, and practice using the place value cards to get them to write 234. I pictured having to teach the child this concept and having to teach them that 2ten is 20, not 2ten zero, which many would write as 200, just like at first they write 2ten 1 as 201, and then we correct them with the place value cards and the use of the abacus to show them that 2ten 1 is written as 21. That is what I was picturing.

Thank you for asking, please let me know if you have any more questions. You can email me directly at Carissa@alabacus.com .

Thank you for giving your child a RightStart in Math,

Carissa
RightStart™ Mathematics by Activities for Learning, Inc.

For program questions: 888.272.3291
To place an order: 888.RS.5.MATH (888.775.6284)
www.RightStartMath.com

Our Mission: To help children understand, apply, and enjoy mathematics


Please let me know if you have any more questions. You can email me directly at Carissa@alabacus.com .