1. EXAMPLE 2 Predicting Results Shopping You buy a T-shirt that costs $9.21. You give the clerk $20.00. Estimate your change. Is this estimate high or low?

2. EXAMPLE 2 Predicting Results $20.00 $9.21 – Shopping You buy a T-shirt that costs $9.21. You give the clerk $20.00. Estimate your change. Is this estimate high or low?

3. EXAMPLE 2 Predicting Results $20 $9 Round 9.21 down to 9. $20.00 $9.21 – Shopping – You buy a T-shirt that costs $9.21. You give the clerk $20.00. Estimate your change. Is this estimate high or low?

4. EXAMPLE 2 Predicting Results ANSWER Your change is about $11. This estimate is high $20 $9 Round 9.21 down to 9. $20.00 $9.21 – Shopping – because you subtracted too little by rounding $9.21 to $9. You buy a T-shirt that costs $9.21. You give the clerk $20.00. Estimate your change. Is this estimate high or low?

5. EXAMPLE 3 Solve a Multi-Step Problem You have $10 to buy bread, milk, and Groceries cereal. If you have enough money, you would like to buy popcorn. The prices of these items are shown. Do you have enough money to buy popcorn?

6. SOLUTION EXAMPLE 3 Solve a Multi-Step Problem You have $10 to buy bread, milk, and Groceries cereal. If you have enough money, you would like to buy popcorn. The prices of these items are shown. Do you have enough money to buy popcorn? Estimate the sum of all the prices, including the price of the popcorn.

7. EXAMPLE 3 Solve a Multi-Step Problem STEP 1 ADD the front-end digits: the dollars.

8. EXAMPLE 3 Solve a Multi-Step Problem STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars.

9. EXAMPLE 3 Solve a Multi-Step Problem STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars.

10. EXAMPLE 3 Solve a Multi-Step Problem $1.79  $2.18 $3.34 $3.65 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars.

11. EXAMPLE 3 Solve a Multi-Step Problem $1.79  $2.18 $3.34 $3.65 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. $9.00

12. EXAMPLE 3 Solve a Multi-Step Problem $1.79 $2.18 $3.34 $3.65 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. $1.79 + $2.18 $3.34 $3.65  $9.00

13. EXAMPLE 3 Solve a Multi-Step Problem $1 $1 $1.79 $2.18 $3.34 $3.65 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. $1.79 + $2.18 $3.34 $3.65 $9.00 

14. EXAMPLE 3 Solve a Multi-Step Problem $1.79 $2.18 $3.34 $3.65 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. $1.79 + $2.18 $3.34 $3.65 $1 $1 $9.00 

15. EXAMPLE 3 Solve a Multi-Step Problem $9 $2 + $1.79 $2.18 $3.34 $3.65 $1.79 + $2.18 $3.34 $3.65 $1 $1 STEP 3ADD your results. STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. $9.00 

16. EXAMPLE 3 Solve a Multi-Step Problem $11 $9 $2 + $1.79 $2.18 $3.34 $3.65 $1.79 + $2.18 $3.34 $3.65 $1 $1 STEP 3STEP 2ESTIMATE the sum of remaining digits: the cents. STEP 1 ADD the front-end digits: the dollars. ADD your results. $9.00 

17. EXAMPLE 3 Solve a Multi-Step Problem Because 11 > 10 you do not have enough money to buy popcorn. ANSWER

18. GUIDED PRACTICE for Examples 2 and 3 Use front-end estimation to estimate the sum. 6.42 + 7.64 + 3.94 + 2.21 3.

19. ANSWER GUIDED PRACTICE 20 for Examples 2 and 3 Use front-end estimation to estimate the sum. 6.42 + 7.64 + 3.94 + 2.21 3.

20. GUIDED PRACTICE Use front-end estimation to estimate the sum. 8.59 + 1.37 + 2 + 6.12 4. for Examples 2 and 3

21. ANSWER GUIDED PRACTICE 18 for Examples 2 and 3 Use front-end estimation to estimate the sum. 8.59 + 1.37 + 2 + 6.12 4.

22. GUIDED PRACTICE Use front-end estimation to estimate the sum. How can you estimate the difference in Example 2 so that your answer is a low estimate? $20.00 $9.21 – for Examples 2 and 3

23. GUIDED PRACTICE Use front-end estimation to estimate the sum. How can you estimate the difference in Example 2 so that your answer is a low estimate? Round 9.21 up to 10. $20.00 $9.21 – $20.00 $10.00 – for Examples 2 and 3

24. GUIDED PRACTICE Use front-end estimation to estimate the sum. How can you estimate the difference in Example 2 so that your answer is a low estimate? ANSWER Your change is about 10. This estimate is low because you subtracted too much by rounding 9.21 to 10. Round 9.21 up to 10. 20.00 9.21 – 20.00 10.00 – for Examples 2 and 3