base-10 blocks in place-value tables

[Chris Clemens]

I have several math books to asses, and I wanted to get some feedback regarding treatment of base-10 blocks as presented in these texts.

Images of these blocks are shown stacked, offset, and in the columns of a place-value chart. (a representative sample is attached)

As you can see, the steps of subtraction, including regrouping, are illustrated by groups of blocks being moved from one column to the next and "dismantled."

In the example, 500 is shown as four 100-piece blocks stacked offset, and one 100-piece block circled, with an arrow pointing to the tens' column of the place-value chart. Then, the whole chart is repeated, with only the offset stack of four, 100-piece blocks in the hundreds' column, and ten new 10-piece blocks in the tens' column. Then the whole arrangement is printed again, but this time the appropriate amount 10-piece blocks appear with a red X showing that these can now be subtracted. (It should be noted here that this print page is the the end of Step 2: which started on the previous print page.)

While I realize that for this grade level, these images should be reproduced as a tactile drawing, help me understand how spreading this across dozens of pages of Braille enhances communicating this relatively simple concept.

Has anyone come up with a compact Braille representation, tactile or otherwise, that can communicate the intent of these images while also keeping related information on the same Braille page?

I appreciate any and all input, even if it is not "officially sanctioned" by NBA.

Respectfully,

Dave R

[Chris Clemens]

Please refer to the answers that have already been added to this question under the Nemeth section of the Forum.
I, too, am very uncomfortable making a suggestion contrary to what the Guidelines and Standards propose. Having said that, they [u]are[/u] guidelines. Rather than using the shape indicator, as you suggested, I think you would be better to use an alphabetic key. As stated on the Nemeth section of the Forum, students are usually give classroom manipulatives (Base 10 blocks) when working with this concept. One of the textbooks that I transcribed used the terms cubes, flats, rods, and ones, but you should use the same terminology as is used in the surrounding text of your book. Obviously, since the contraction for one is only 2 cells, it would not have to be keyed.
At times, these are depicted with a group of 10's being moved to the ones to show the carrying of numbers for subtraction, or vice versa for addition. In such a case you would still need a tactile graphic to circle the symbols used and an arrow showing where they are moving. Alternatively, if you are going to have to create a tactile anyway (to show movement), you could make a simplified shape (a large square for 100 without showing the individual squares, a long rectangle for the 10's without showing the individual squares, and a small square for the ones). These would also have to be explained in a transcriber's note. In books where there are several pages of Base 10 blocks the first couple at least should be done as tactiles according to the Guidelines and Standards, and then your modified method explained and used for the rest.

Betty

[betty.marshall]

Thank you for this reply. It is good to get feedback from many perspectives.

Dave R
edited by braillepro on 7/23/2013

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