Directions

1. For each unit in your student book, there are two online Brain Teasers. If you get stuck, click on the Hints button for a strategy to help solve the question. Once you find the answer to the question, click on the Solution button to see if you are right.
2. The hints often suggest problem-solving strategies. Here are some of the strategies you might try:
   • Write a Number Sentence
   • Write an Equation
   • Draw a Picture
   • Make a Table
   • Act It Out
   • Guess and Check
   • Find a Pattern
   • Work Backward
   • Make a List
   • Solve a Simpler Problem
   • Choose a Strategy
   • Use Logical Thinking
3. In solving the Brain Teasers, try this four-step procedure: Understand, Plan, Solve, and Look Back.

Understand

• What is the question?
• What facts do you know?

Plan

• Have you ever solved a problem like this before?
• If you missed something, try the problem again.

Solve

• Try your plan.

Look Back

• Do the answers match the facts in the problem?
• If you missed something, try the problem again.