$1000 X 9% X 9/12=

My question is how do I multiply 9/12 ?

Take 9/12 apart -- divided the 9 by 3 and that equals 3.
Then divide the 12 by 3 and that equals 4.
You now have 3/4 where prior to this you had 9/12.
3/4's is the same as 75 %.
3/4 or 75 % of $90. Is $ 67.50.

Thank you so so much RichardBondMan.

Or a Simpler Way:
Take the 1,000, multiply it by the 9% (which is 0.09), then multiply it by 9 and divide by 12

Captainforest, thanks for showing me a simpler way.