How can you use a quick picture to find 3 times 2.7

3x2.7=8.1,,, im not sure this is what you were asking for but i hope it helps

XoXo

Draw 2.7 3 times. (im not sure how to do 2.7)
  (sample 8*6)

1. use the equation y -y1 = m(x-x1)
2. (-6,-4) is x1,y1 and (4,-6) is x2,y2
3. y-(-4) = m(x-(-6)
m is the gradient, 10/10, which is 1. make two negatives into a positive.
4. y+4 = x+6

therefore the equation of the lines is y = x+2

substitute the points back into the equation to double check.