To do this trick, you'll need 2 dice. Dice are made up so that opposite faces add up to 7. Make sure that 6 is opposite 1, the 5 is opposite 2, and the 4 is opposite 3.
Roll the dice:
1. multiply the top two numbers
2. multiply the bottom two numbers
3. multiply the top of one dice by the bottom of the other
4. and now multiply the other top and bottom
Now add up all of your answers, and it always adds up to 49.

I need to figure out why this always adds up to 49. I actually need an equation.
PLEASE HELP ME.

https://www.cut-the-knot.org/Outline/Arithmetic/TwoDice.shtml