Acid Rain: Sources and Impact
Scientist and climate change expert Michael Oppenheimer discusses the causes and impact of acid rain. Oppenheimer states that the primary sources of acid rain are emissions of sulfur dioxide and nitrogen oxides from elec..
Acquisition of Biases, The
Social psychologist Mahzarin Banaji explains that prejudice is something that is learned, not something with which we're born. The good news, according to Dr. Banaji, is that we can change our thinking. "It's part of ord..
Adams Presidency, The
Historian Peter Onuf talks about the high points as well as the shortcomings of the John Adams presidency. On the downside, President Adams had to contend with an extremely disloyal Cabinet, consisting largely of holdove..
Addicted to Plastic
From styrofoam cups to artificial organs, plastics are perhaps the most ubiquitous and versatile material ever invented. No invention in the past 100 years has had more influence and presence than synthetics. But such pr..
Addicted to Plastic (short version)
From styrofoam cups to artificial organs, plastics are perhaps the most ubiquitous and versatile material ever invented. No invention in the past 100 years has had more influence and presence than synthetics. But such pr..
Addictive Personalities
Dean Hamer, Director of the Gene Structure and Regulation Unit at the National Cancer Institute, talks about so-called "addictive personalities." He explains that the term itself is probably a misnomer, because there is ..
Adding Fractions With the Same Denominator: Adding Fractions With the Same Denominator
This clip explains how to add fractions with the same denominator. It states that the sum will be a fraction with the same denominator as the original one, and a numerator which consists of the original numerators added ..
Adding Fractions With the Same Denominator: Adding Mixed Numbers
This clip explains how to add mixed numbers. One method is to add the whole numbers and the fractions separately and combine the results. Another approach is to convert the mixed numbers to improper fractions, then add a..
Adding Fractions With the Same Denominator: Adding More Than Two Fractions
This clip explains that adding more than two fractions with the same denominator is a two-step process. The first step is adding the numerators; the second step is converting the improper fraction that results to a mixed..
Adding Fractions With the Same Denominator: Changing Improper Fractions to Mixed Numbers
This clip explains the procedure of changing improper fractions to mixed numbers. It also provides a shortcut for this operation: dividing the numerator of the improper fraction by the denominator.