Please choose the correct ending to complete the given sentence: Health: [header] How to add a consecutive series of numbers in your head [title] Imagine the numbers. [step] Let's suppose that you want to add all the numbers from 1 to 100 in your head. Imagine that on a table in front of you you have arranged stacks of pennies, in a long neat row left to right, to equal each of these numbers.

Ending1: These stacks should in turn equal the number of quarters. [substeps] This counting method simplifies the math involved, a matter of time. Ending2: For example, the first stack of pennies starting on the left side of the table is just one penny by itself. Beside it, to its right is a stack of 2 pennies. Ending3: [title] Imagine you have a list of all the numbers in that row. [title] Sit down and write down that list-list in order from 1-10. Ending4: In our example, the rows on the left stack of pennies would go from 1 to 100 in your head. In our example, the rows on the right stack of pennies would go from 1 to 100.

Answer format: ending1/ending2/ending3/ending4