What you need to know before I explain is how to add percents onto numbers. What I'm saying is what and how to do 6.4% x 1500
1. You can't do a percent and number together, that's impossible
What you can do is convert the percent (6.4%) into a decimal
2. 6.4% is equivalent to 6.4/100, which is equivalent to 0.064
3. Now, you multiply 0.064 x 1500
You will notice, hopefully, that you have a number smaller than 1500, but do not panic, you are on the right track!
4. Using the number you got, add that to 1500, and there's your total!
But, if you want only the tax, keep that small number you started off with!