(not homework…mine or anyone elses)

So, I’m doing that Christmas savings thing where you put away a dollar amount each week based on what week of the year it is.

IOW week 1, you put away $1, week 2, $2, Week 3, $3, and so on to week 52.

What I’ve been doing though is, whenever I have a few extra bucks in my pocket, I’ll stick in the envelope. Or, if for example it’s week 3 and I have a $5 bill, I’ll just put the whole $5 and mark off week 3.

Then every once in a while I’ll count the money and verify what week I’m paid up to. (we’re in the 9th week of the year and I’ve saved through week 20 already )

I imagine there must be some formula for easily figuring out how much $ should have been saved by a certain week.

But, for the life of me, my 47 year-old brain can’t reach far enough back to my 8th grade algebra class to figure it out.

So, I’m stuck with getting out the calculator and punching in “1+2+3+4+5…” to find the answer.

Is there a formula to easy calculate the result?