7 and 4/9 or 67/9
67
If you use 6 plus signs, here's what you'll get: 9 + 8 + 7 + 6 + 5 + 43 + 21= 99
First, put a division sign between the first and second nine, like this: 9/ 9. Then, put a plus sign between the one and the ninety-nine to make one hundred. 99+9/9=100 or 9/9+99=100
It is a number between 8 and 9, more precisely 8.185352771872...
9 + 8 + 7 + 65 + 4 + 3 + 2 + 1 = 99, so 7 plus signs.
35
72, 108
4,5,6
9+8+7+65+4+3+2+1 = 99. So 7 addition signs need to go in 987654321 to get a total of 99.
9 x -67 = -58
67 x 9 = 603