Understanding and tracking time is key to keeping society -- and our lives -- running smoothly. Early civilizations developed calendars with just 300 days in a year. But by 1582, the time it takes for Earth to rotate around the sun was better understood, and Pope Gregory introduced the 365-day Gregorian calendar -- the one used by most of the world today. Listen to hear a scientist explain the math behind adding and subtracting leap days to keep the calendar aligned with the Earth’s movement, and learn how Christianity played a role in the calendar’s creation.
The Roman Empire was one of the largest and longest lasting in history. Theories about what led to its collapse have ranged from the barbarian invasions to internal corruption to economic instability. However, a recent theory that is added to the mix is climate change. New research has contributed to the theory that climate change destabilized Rome and made it vulnerable to collapse. In this audio story, this theory is discussed, including the scientific evidence, specifically the study of tree rings, that supports it. There is also discussion about whether this was naturally occurring or a man-made phenomenon.
The Lexile Audio Measure is an indicator of the complexity of an audio passage. It is based on a scientifically developed scale with a maximum score of 2000L.How to Use Lexile Audio Measures
Find stories at the right level of complexity for your students, so that they will be challenged without being frustrated. The measures are categorized into low, medium, or high in order to aid teachers in story selection when they do not know students’ Lexile listening levels.
|Listening Level||Lexile Audio Measures|
These recommended ranges are for instructional use of Listenwise audio content in combination with supports such as the interactive transcript, etc.
|Grade||Lexile Audio Measures (Recommended Ranges)|
|1||215L - 610L|
|2||490L - 855L|
|3||725L - 1060L|
|4||945L - 1250L|
|5||1045L - 1350L|
|6||1125L - 1430L|
|7||1190L - 1500L|
|8||1250L - 1555L|
|9||1300L - 1610L|
|10||1345L - 1655L|
|11/12||1385L - 1695L|