## Monday, March 23, 2009

### Base Ten Blocks

I am preparing materials for teaching Grade 3 math using My Pals are Here 3A. I can use paper cut-out versions of the base ten blocks for tens and ones and possibly hundreds but I am having a problem with the thousands place. For Grade 3, the numbers go up to 10 000. Since we do not have the physical base ten blocks available, I am considering other options to represent the thousands, hundreds, tens and ones. I was considering making sketches of marbles in a jar. It is easy to make sketches of bottles of ten marbles, hundred marbles and thousand marbles. I am worried about the fact that the model may not be a proportionate one and will affect students' understanding.
Geoff, a teacher in the Philippines
Since you are using sketches, why not use diagrams of thousands, hundreds, tens and one (as in the textbook). I suppose the third graders can do without the actual base ten blocks as they have used it in first and second grades. The idea of converting a ten into ten ones etc should be well developed by the third grade. However, a pictorial representation is still necessary to help students to visualize numbers and operations such as addition, subtraction, multiplication and division which they will learn later in the third grade.
I suggest you substitute the actual base ten blocks with pictorial representation such as the ones you see in the textbooks.