Dawn,

Thank you for your message. You bring up an interesting idea and I did mention it to Dr. Cotter just to see what her thoughts were.

She said, "The Base-ten Picture cards are used to add 4-digit numbers together with trading (see Lesson 35 in Level B). The biggest problem with the set of the set of blocks is that they contain only 1 thousand and 10 hundreds, but 9 thousands and 27 hundreds are needed. The pictures also are another step toward abstraction because they are the same size just as the digit representing 7 hundred is the same size as the digit representing 7 ones."

I hope this helps, please let me know if you have any other questions.

Make it a great day,

Cassie
Activities for Learning-RightStart™ Mathematics
Cassie@ALabacus.com
www.ALabacus.com

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