Step 1 Objective

Describe and extend number sequences: count on or back in tens or hundreds, starting from any two- or three-digit number.


Probing questions

If you count in tens from 42, which digit changes? Why doesn't the ones digit change?

If you start with 93 and count back in tens, what would be the smallest number you would reach on a 1-100 grid? Would 14 be one of the numbers you say? Why not?

What do you notice when I subtract 10 from a number? Can you explain?