One point Five ... OR One and a Half
Fifteen
It's written as.. fifteen
15 = fifteen
fifteen minus b
fifteen million
" fifteen minus 'bee' "
Fifteen degrees.
You already have in the question.
15
15 million, seven hundreds and sixty-three thousand, one hundred an forty-five
Write "9" then the forward slash "/" and then "15". Or you can write the 9 above a horizontal line with the 15 below that line.
There is more than 15 instruments techniques. Some of the techniques would be blow in, blow out, spit, line up and have fingers in place.