1. Big Idea There is more than algorithm for each of the operations with rational numbers. Most algorithms for operations with rational numbers use both mental math and paper and pencil. Essential Understanding/Question 17 -1 How can you use mental math to add multiples of 100 to a three- digit number?

2. Build, draw, or write to find the missing addend using your choice of one of the problems in the box. Describe how you used mental math to find the missing addend in one of the problems in the middle box? Create a story with a 3 or 4 digit number that you are joining to a 3 digit number with a zero in the tens and the ones place. Create your own 3 or 4 digit number sentence adding a 3-digit number that has zeros in the tens and ones place. 32 + ______ = 232 496 + _____ = 996 _____ + 400 = 782 3, 429 + ______ = 3, 729 17 - 1

3. Big Idea Numbers and calculations can be approximated by numbers that are close and easy to compute mentally. (17-2) Essential Understanding/Question How can you estimate sums of three-digit numbers?

4. Show two different ways to estimate the sum. How does estimating help you find a reasonable answer. Create a n addition word problem using an estimation strategy. Explain how you estimated to find the sum. How can you estimate sums of one of the following problems. 423+187 1,423+2, 370 (17-2)

5. There is more than algorithm for each of the operations with rational numbers. Most algorithms for operations with rational numbers use both mental math and paper and pencil. Essential Understanding/Question 17-3 How can you model and record adding 2 three-digit numbers?

6. Draw, build, or write an addition sentence using 2 three-digit numbers. Find the sum of 2,743 and 397. Create an addition story using 2 three-digit numbers that requires regrouping. Explain why you did or did not have to regroup. How can you model and record adding 2 three- digit numbers? 17 - 3

7. Big Idea There is more than one algorithm for each of the operations with rational numbers. (17-4) Essential Understanding/Question How do you add three-digit numbers using paper and pencil ?

8. Draw or write how to regroup the problem you chose. Show another way to solve the problem you chose. Create a word problem using the number you chose. Explain how regrouping is used to solve this problem. Your Choice 369+531 1,522+478 (17-4)

9. Big Idea There is more than algorithm for each of the operations with rational numbers. Most algorithms for operations with rational numbers use both mental math and paper and pencil. Essential Understanding/Question 17 – 5 What strategy can you use to find the missing part?

10. Draw, build, or write one way to solve one of the problems in the box. Find the missing part of one of the problems in the box. Create an addition story problem that matches one of the number sentences in the box. Explain how you solved one of the problems in the box. 400 + _____ = 860 460 + ______ = 930 _______ + 370 = 560 ______ + 2,100 = 4, 310 17 - 5

11. Big Idea Numbers and calculations can be approximated by numbers that are close and easy to compute mentally.( 17-6) Essential Understanding/Question How can you estimate differences of three-digit numbers.

12. Show how you would estimate to find the difference of one of the problems. How does estimating help you find a reasonable answer. Create a subtraction word problem using an estimation strategy. Explain how you estimated to find the difference. Your Choice 769-227 3,105-1,638 (17-6)