Let's write 746,936,015 in expanded form:
7 * 100,000,000
4 * 10,000,000
6 * 1,000,000
9 * 100,000
3 * 10,000
6 * 1,000
1 * 10
5 * 1
Now, we can summarize:
7 * 100,000,000 + 4 * 10,000,000 + 6 * 1,000,000 + 9 * 100,000 + 3 * 10,000 + 6 * 1,000 + 1 * 10 + 5 * 1