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## Mental Math: Doubling and Halving

Summary
The content focuses on a mental math trick of doubling and halving to simplify multiplication problems, particularly useful for the GRE exam's Quant section.
• Doubling one factor and halving the other in a multiplication problem does not change the product, making calculations easier.
• This trick is especially useful when one of the factors ends in 5 or 50, as doubling it results in a round number, simplifying the multiplication.
• Practicing this trick can significantly speed up calculations, saving valuable time during the exam.
• The trick can be applied multiple times in succession for factors like 25 or multiples of 25, further simplifying calculations.
• Examples and practice problems demonstrate how to apply this trick effectively, highlighting its utility in making seemingly difficult calculations manageable.
Chapters
00:00
Introduction to Doubling and Halving
00:16
Applying the Trick
02:06
When to Use the Trick
02:53
Practical Examples
05:37
Summary and Importance