The document explains place value using the number 784 as an example. It states that 784 has three digits in the hundreds, tens, and ones places. The hundreds place represents how many hundreds are in the number, which is 7 hundreds for 784. The tens place represents how many tens are in the number, which is 8 tens for 784. The ones place represents how many ones are in the number, which is 4 ones for 784. Therefore, the number 784 represents 7 hundreds, 8 tens, and 4 ones.