3:4 = G:B
1:5 = Mr. Smith's class: 7th Grade
2:7= 7th: Middle school
12 girls = 3 units
1 unit = 12/3= 4
Boys = 4x4= 16
<em>Whole class = 28 students</em>
Class : Grade = 1:5 <em> 7 = number of units in Mr. Smith's class</em>
28 = 1 unit
5 units= 28x5= 140 <em>There are 140 kids in the grade</em>
140 = 2 units
1 unit = 140/2= 70
70x7=490
<u><em>There are 490 students in the whole grade</em></u>
OK.......
Evaluating [(21 + 6) - 32] 2 * 9

Your answer would be
-90
H0P3 It H3LPS :)
1/8=0.125 1%=0.01 11%=0.11
1%, 0.09, 11%, 1/8