To get the number 100 using four sevens (7’s) and one (1), we need to carefully arrange these numbers with mathematical operations. One possible solution is:

$177 - 77 = 100$

Here’s how it works:

1. Combine three 7's and 1 to form 177.
2. Subtract 77 (which uses the remaining two 7's).

The calculation is:

$177 - 77 = 100$

This solution meets the requirement of using exactly four 7's and one 1.

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Would you like more details or have any questions?

Here are five related questions you might find interesting:

1. Can you form 200 using four 8's and one 2?
2. How would you use three 5's and two 1's to make 20?
3. What is the smallest number you can make with four 3's?
4. How can you make 50 using four 9's and one 1?
5. Is it possible to make 10 using only three 4's?

Tip: Combining numbers and using mathematical operations creatively can lead to interesting solutions!