Give the step-by-step reasoning process and then the final answer. Shane prepares sandwiches for the Boy Scouts. He buys 2 packages of sliced bread containing 20 slices each, and he also buys 2 packages of sliced ham containing 8 slices each. Shane will make as many sandwiches as he can according to the ham he has. How many slices of bread will he have leftover?
With 2 packages of sliced ham, Shane has 2 * 8 = 16 slices of ham. Since he has 16 slices, Shane makes 16 sandwiches. With 2 packages of sliced bread, he has 20 * 2 = 40 slices of bread. To make the 16 sandwiches, he needs 16 * 2 = 32 slices of bread. He has 40 - 32 = 8 slices of bread leftover.
The final answer: 8.