For what it's worth, I got a "U" in maths GCSE back in the 80s. I show a lot of symptoms of Dyscalculia...I can't work out basic problems. I begin ok then spiral into confusion.
Here's the basics as simply as I can put it. If I've made mistakes someone will hopefully ask about them.
I have a client for whom I write weekly blogs and do a bit of social media too. He pays monthly when I invoice. It's a new arrangement.
When we started I told him the price was $250 a week or $1000 a month. At the first week he paid half up front...so $500.
Then when last week it was time to bill him for the next month which begins today I billed him $1000 again. which is 500 for work done last month and 500 in advance for work yet to be done this month.
He then said he wanted more work from me and how much would it cost. I said it would be $400 per week and he was happy.
But now...he's paid 500 in advance for this month and next months bill will now be larger. How much do I bill him for next month and the month after that? how do I now make it all balance out?
Try as I might I can't seem to work it out. I keep getting confused! I'm a creative...no good at maths.