Follow carefully and you will see why I am such a good teacher.  I posted this in 2014 and had several likes but only two or three of you were with me then.  I enjoyed it too much to pass it up for another use.

Letter written to my grand-son, Dan.  Dan was an adult. I was just  spoofing common core a bit!  If you like common core, handle me with grace and forgiveness.  😀  If you don’t like it, have a laugh!

Dan Hayes, surely you would not question my being a proponent of common core! Proof is in the pudding.  So let me explain.

I was eighty-one last year so how old am I this year – after birthday has passed of course, (if 2016’s birthday has not yet occurred this example I am giving is not the right way to figure my present age), but back to 81 last year, birthday has happened this year so how old am I now (and of course, I will be this number of years for the remainder of 2016, we will not bother with fractions at this point). In fact I will be this number of years up to my birthday in January, 2017. That is if you round figure to the lowest even year. No, I don’t mean even year like odd/even – I mean like the total of years I have lived for the complete rotation of the earth around the sun, or is it the sun around the earth? Which is right? That’s common core science; I haven’t studied that out too well.

Now back to our math question. If I was eighty-one last year, sorry that should if I “were” eighty-one, no that’s not the right mood, maybe not mood, but when stating something that might not be, which is sometimes signaled by the word “if”, you are to use “were” not “was” – is it the same in common core grammar?  I don’t know common core grammar very well.

Well, let’s assume it is the same, so back to my question. If I were eighty-one years old at my birthday anniversary on January 24th in 2015, how old will/would I—no, how old am I now. No, how old was I on January 24,  in this our present year, 2016.

Shall I repeat the question? Oh, you understand the question. Good, let’s go on to how to work out the solution. Write down 8 x’s, each x will represent the number 10 (which is the first numeral that contains two digits—that is if you do not consider negative numbers). You can write these x’s in either a horizontal or vertical direction – you might want to clump them together like a ball or put them in a circle, or you might want to make an imaginary car with an x used to represent each focal point on the car. Just anyway will do. Now make a row of 10 slashes, draw a line underneath to show that they represent the next set of ten (which by the way, I will need when I reach ninety). But I am not really ninety yet so you will need to mark off a slash for each year that I lack being ninety. See mark off one for eighty-one, two for eighty-two, three—you understand, oh, good. Now when you get to eighty-nine, you will have one slash left. Change it to an x and put it with your other eight x’s, the one’s you used to draw the car. Hold those eight x’s in your head – no just imagine them – put the one slash with them, how many is that?

Yes, you can use two fingers to represent the two if you want to. Maybe that is better than the slash. Why not just have eight buddies come up and each of you will hold up ten fingers, we need another buddy to hold up two fingers. Now let’s count the fingers. Why fingers? Because they will each represent one year, that’s a full rotation of the earth around the sun.

Let’s take a break and go to lunch.  I’ll buy us both a sandwich.  Yes, that will be two as you can show by holding up two fingers.  I should have said “I’ll buy us each a sandwich.”  I didn’t mean one sandwich for both of us – yes, I know that’s what I said, but I changed….