Ep 4. Divide and Conquer

In season 1 episode 4 of Secrets of Mental Math, titled Divide and Conquer, viewers are taken on a journey through various mental techniques for dividing numbers quickly and efficiently. The episode begins with a brief review of basic division principles before diving into more advanced methods.

The first technique demonstrated in the episode is called "guess and check". This method involves using estimation skills to quickly determine an approximate quotient, then tweaking the numbers until the correct answer is reached. This method is particularly useful when dividing large numbers by small numbers, as it allows for quick mental calculations without needing to resort to a calculator.

Next, the show introduces the "long division" method, which many people may be familiar with from their school days. However, the episode presents a simplified version of long division that is easier to do mentally, and showcases how this method can be used to divide larger numbers.

The third technique explored in the episode is known as "short division", which involves simplifying the problem by dividing each digit of the dividend by the divisor one at a time. This method is particularly useful when dividing large numbers by a small divisor, and allows for quick mental calculations without relying on estimation.

The episode also covers the idea of "casting out nines", a method used to check division problems for errors. By adding up the digits of each number and checking the resulting sum against a predetermined value (in this case, the number 9), viewers can quickly determine whether they have made a mistake in their calculations.

In addition to these techniques, the show introduces a variety of mental tricks and shortcuts that can be used to solve division problems quickly. For example, viewers are taught how to identify patterns in numbers and use these patterns to quickly determine their divisibility by certain factors. The episode also explores the idea of "reciprocal division", where the divisor is flipped and turned into a fraction that is then multiplied by the dividend.

Throughout the episode, viewers are given ample opportunity to practice these various techniques and tricks through a variety of examples and puzzles presented on screen. The host, Arthur Benjamin, guides viewers through each step of the process, breaking down even the most complex calculations into simple, easy-to-follow steps.

Overall, season 1 episode 4 of Secrets of Mental Math, Divide and Conquer, is a highly informative and engaging exploration of mental techniques for division. Viewers will come away from the episode with a wealth of new skills and strategies for solving division problems quickly and accurately, whether they are working with large or small numbers.