Bear Problem

Here is an example of the type of math problem I've been asking the students to solve the past two days.  We've started each math class with a question like this.

About how much more do three female black bears weigh compared to three male sun bears?  Without finding the exact values, tell how you can solve this problem.

Weight

Type of Bear	Female	Male
Sun Bear	78 pounds	95 pounds
Black Bear	215 pounds	345 pounds