## Question 4

### Place these numbers in order of largest to smallest: .00156, 1/60, .0015, .001, .002

One sixtieth is the biggest of these, as the others are between one and two one-thousandths (or between one one-thousandth and one five-hundredth).

Then, in descending order, we have .002, .00156, .0015 and .001.

It is common that students will order the decimals this way:

.00156, .0015, .002, .001

I cannot predict where a person who does this will place one sixtieth.

Nonetheless, when we read these decimals as *point zero zero one five six,* we encourage students to ignore place value, and we encourage the misapplication of whole-number rules to the right of the decimal point.

We really do need to use place value language for decimals in classrooms. *One-hundred-fifty-six one-hundred-thousandths.*

Much, *much* more about this and related ideas in the Triangleman Decimal Institute posts from last fall. Short version: learning decimals is * WAY* more complicated than most people have any reason to imagine.

I think the use of the appropriate decimal language gets lost quickly, at least in my classroom, and I assume in the middle and high schools where my students arrive from. Thanks for that.