Final answer:
To estimate the number of pictures per folder, we divide 1,424 by 7. The best estimate for the number of pictures Nadine should put in each folder is about 200, making 'a' the correct answer choice.
Step-by-step explanation:
The student is asking about how to divide a total number of items (pictures) evenly into groups (folders). This is a division problem, which is a concept in mathematics. Specifically, Nadine has 1,424 pictures that she wants to divide into 7 folders.
To estimate the number of pictures per folder, we can round 1,424 to the nearest thousand, which is 1,000 for easier calculation. When 1,000 is divided by 7, it gives you slightly more than 100 pictures per folder. However, since we rounded down from 1,424 to 1,000, our estimate must be more than 100 pictures per folder.
To find a more accurate estimate, think about how many times 7 fits into both 1,000 and 400 (since 1,424 is composed of 1,000 and 424). 7 goes into 1,000 about 142 times, because 7 x 140 = 980, which is close to 1,000. It goes into 400 about 57 times, because 7 x 50 = 350, and we have a little over 50 left. Adding both estimates (142 + 57), we get about 200 pictures per folder. Therefore, the answer is about 200 pictures in each folder, making 'a' the correct choice.