Draw to show how you can use models to compare 345 and 391

We can represent each of these numbers using blocks of hundreds, tens and ones.

For the first number (345), we will draw:
3 blocks of hundreds
4 blocks of tens
5 blocks of ones

For the second number (391), we will draw:
3 blocks of hundreds
9 blocks of tens
1 block of ones

Now, we will compare the blocks in the two numbers:
For the hundreds: each of the two numbers has 3 blocks of hundreds. Therefore, the hundreds are equal
For the tens: the first number has 4 blocks of tens while the second number has 9 blocks. This means that the tens in the second number is more.

Based on this, we can say that the second number (391) is greater than the first number (345)

The answer is part a: use