Proportion Calc

1.0：2.0＝Ｘ：6.0
It's a simple proportion calculation.

Can you solve the following equations immediately?
1.0：2.0＝Ｘ：6.0
2.0Ｘ＝6.0
Ｘ＝3.0

If you do not understand the meaning of the proportion calculation,
it might give you hard time.
The app gives you a right answer quickly, if only you put figures into
box of a2 or b2. It calculates based on proportion of "a1:b1".
The triangular figure helps you with imaging a proportion.
At the same time, its hypotenuse is also calculated.

What's a so convenient app!
Why don't you buy it?