What is the estimate of the sum of 304, 613, 840, and 434 using front end estimation? A. 2,000 B. 2,100 C. 2,200 D. 2,300

Front-end estimation is a particular method of estimation that involves the numbers' "front" digits. Here's how you can estimate the sum of 304, 613, 840, and 434 using front-end estimation:

1. First, look at the "front" digits of each number. These are the digits in the hundreds place for each of these four numbers. For 304, it's 3 (representing 300). For 613, it's 6 (representing 600). For 840, it's 8 (representing 800). And for 434, it's 4 (representing 400).

2. Next, add these front digits together: 3 + 6 + 8 + 4 = 21.

3. Because we were working with hundreds (the front digits were in the hundreds place), the sum we got needs to be understood as being in hundreds as well. So, 21 here means 2100.

So, the estimate of the sum of 304, 613, 840, and 434 using front-end estimation is 2100. Therefore, the answer is B. 2,100.