PBS
How Do You Measure the Size of the Universe?
The universe is HUGE. But, there is only so much of the universe we can ACTUALLY see, and if we wanted to measure that FINITE space, how would we do it? A gigantic ruler? One really long car ride? Or maybe it's something even more...
KnowMo
Converting Decimals into Fractions
This is a lecture video that explains how to convert decimals into fractions. The presenter begins by defining what fractions are and pointing out the importance of understanding place value. They then go on to list common decimal to...
Math Mammoth
Math Mammoth: Multiplication of Fractions and Area of Rectangles
Demonstrates using visual models of rectangular arrays how to multiply fractions and how this can be used to find the area of rectangles. [8:02]
Math Mammoth
Math Mammoth: Area of Rectangles and Rectangular Shapes
Demonstrates how to find the area of a rectangle using unit squares. [9:53] CCSS.Math.Content.3.MD.C.7.a Find the area of a rectangle with whole-number side lengths by tiling it. CCSS.Math.Content.3.MD.C.7.d Recognize area as additive.