1. Splash Screen

2. Lesson Menu Five-Minute Check (over Lesson 2–2) Main Idea Example 1:Problem-Solving Strategy

3. Main Idea/Vocabulary I will solve problems by using the work backward strategy.

4. Example 1 The Nature Club raised $125 to buy and install nesting boxes for birds at a wildlife site. Each box costs $5. It costs $75 to rent a bus so the members can travel to the site. How many boxes can the club buy?

5. Example 1 Understand What facts do you know? $125 is available to buy and install the nesting boxes. Each box costs $5. The bus costs $75. What do you need to find? How many boxes can the club buy?

6. Example 1 Plan You can work backward to find the number of boxes that can be bought. Start with $125, the amount the Nature Club has raised. Then subtract the costs. Recall that subtraction “undoes” addition and that division “undoes” multiplication.

7. Example 1 Solve First, undo the addition of the cost of the bus by subtracting the cost of the bus. $125 – $75 = $50 Then undo the multiplication of the cost of the boxes by dividing by the cost for each box. $50 ÷ $5 = $10 Answer: So, ten boxes can be bought.

8. Example 1 Look back at the problem. Since 10 × $5 = $50 and $50 + $75 = $125, the answer is correct. Check

9. End of the Lesson End Lesson

10. Resources Five-Minute Check (over Lesson 2–2) Image Bank Math Tool Chest Add and Subtract Decimals

11. 1.A 2.B 3.C 4.D Five Minute Check 1 (over Lesson 2–2) A.11 B.10 C.10.5 D.9 Estimate 5.3 + 6.1 by rounding.

12. 1.A 2.B 3.C 4.D Five Minute Check 2 (over Lesson 2–2) A.9,000 B.10,000 C.10,900 D.9,500 Estimate 1,319 + 8,640 by rounding.

13. 1.A 2.B 3.C 4.D Five Minute Check 3 (over Lesson 2–2) A.23 B.20 C.30 D.15 Estimate 50.3 – 26.1 by using compatible numbers.

14. 1.A 2.B 3.C 4.D Five Minute Check 4 (over Lesson 2–2) A.10 B.9 C.10.1 D.11 Estimate 18.63 – 9.21 by using compatible numbers.

15. 1.A 2.B 3.C 4.D Five Minute Check 5 (over Lesson 2–2) A.320 B.305 C.310 D.315 Estimate 257.3 + 52.8 by using compatible numbers.

16. End of Custom Shows