As a math geek, I often find myself using math language to describe everyday life. For example, if I don't think that someone is credible, I might say "just take what he has to say and multiply by ...

Students write multiplication equations based on groups of objects using zero and one.

Multiply by 0, 1, and 10 using the grouping of objects, counting by tens, and arrays.

8 642 4 1284 2 2568 1 5136 The rows for 8, 4, and 2 are even, so they represent multiply by zero in the long multiplication. You can cross them out. That leaves the row for 17 and 1.

So if our goal is to divide by 10 it may be easier to think of it as multiplying by 0.1. To fit well with powers of two, we really want to think about multiply the whole thing by 0.8 and then ...