Identify Sub-Problems

1. Identify Sub-Problems Problem Solving Strategy

2. Identify Sub-Problems This strategy is awesome to implement when a problem seems overwhelming and very complicated. But, after you break them down into their sub-problems, you can start to see how to attack the problem.  Taking a problem and breaking it into parts allows you to identify the hard parts and concentrate on solving them without being overwhelmed.  Sub-problems involve organizing your plan of attack, unlike other strategies that organize data. Identify your sub-problems with questions.

3. Identify Sub-Problems Change your focus in this strategy. Your focus needs to change from the big problem to the sub-problems or sub-goals. Once the sub-goals are solved then you should focus on solving the big problem. Many complex activities, such as manufacturing automobiles are broken down into sub-problems. At one station, the windshield goes on, at another the doors are attached, then the hood, the brakes, etc. The basis of the assembly line is to brake down tasks into sub-problems.

4. PAINT Problem A mixture is 25% green paint, 30% blue paint, and 45% water. If 4 quarts of green paint are added to 20 quarts of the mixture, what is the percentage of green paint in the new mixture?

5. Ask questions: What do you need to know? How many quarts of green paint are in the new mixture? How many quarts of paint are in the new mixture? What percentage of the new mixture is green paint?

6. Ask questions: What do you need to know to answer these questions? How many quarts of green paint are in the new mixture? How many quarts of green paint are in the original mixture? And how many quarts of paint are in the original mixture?

7. Rearrange the list in an order that the questions can be answered. How many quarts of paint are in the original mixture? How many quarts of green paint are in the original mixture? How many quarts of green paint are in the new mixture? How many quarts of paint are in the new mixture? What percentage of the new mixture is green paint?

8. Solve the sub-problems in order. How many quarts of paint are in the original mixture? How many quarts of green paint are in the original mixture? How many quarts of green paint are in the new mixture?

9. Keep solving. How many quarts of paint are in the new mixture?  What percentage of the new mixture is green paint?

10. Strategy – Identify Sub-Problems Ask questions: What do you need to know? Ask more questions: What do you need to know to answer the first questions? Stop when you have questions you can answer. Rearrange the list in an order that the questions can be answered. Solve the sub-problems in order.

11. Now it’s your turn… Open your problem solving book and go to the section on Identify Sub-problems (pages 17-18). Print off a problem solving sheet and do a complete solution to a problem from this section…do one and submit it or do more for “extra fun”. (ISU Bookstore, The Car Bargain, and/or Test Average) Email your complete solution, with your steps clearly shown to NCAMath@district87.org or put them in Nancy Powell’s mail box! Have fun and Problem solve!