Estimation and Subtraction the ''New and Improved Way''
My son has missed school due to being ill and now I have to ''teach'' him how to do his math work. I am familiar with rounding and estimating but they have introduced new ways to estimate which in turn confuse me. So I am going to scan the math problem and attach it on here. Please please please help me understand what this question is asking. I have looked and searched for help and even the textbook website doesn't explain this stuff where I can understand.
Question # 21:
Write a problem using estimation and subtraction. Use the table at the right. Tell which method you would use to estimate the difference. Explain your choice.
| Sea Turtle
| Weight In Pounds