Learn more about ATP: how it stores energy, and how that energy is released when it's converted to ADP and phosphate. Created by Sal Khan.

Kahn Academy video - How to add and subtract fractions with like and unlike denominators.

To add the vectors (x₁,y₁) and (x₂,y₂), we add the corresponding components from each vector: (x₁+x₂,y₁+y₂). Here's a concrete example: the sum of (2,4) and (1,5) is (2+1,4+5), which is (3,9). There's also a nice graphical way to add vectors, and the two ways will always result in the same vector.​​

An introduction to probability through the example of flipping a quarter and rolling a die. it is a practice lesson.

Alcohol or ethanol fermentation, including yeast and its role in bread and wine production.

A gene as a stretch of DNA on a chromosome. Alleles as versions (sequence variants) of a gene.

Neurons (or nerve cells) are specialized cells that transmit and receive electrical signals in the body. Neurons are composed of three main parts: dendrites, a cell body, and an axon. Signals are received through the dendrites, travel to the cell body, and continue down the axon until they reach the synapse (the communication point between two neurons).

DNA is composed of two strands of nucleotides held together by hydrogen bonding. The strands each run from 5' to 3' and run in antiparallel, or opposite, directions from one another.

This arithmetic lesson demonstrates more long division problems with remainders.[Arithmetic playlist: Lesson 26 of 38]

You get the general idea of decimal is and what the digits in different places represent (place value). Now you're ready to do something with the decimals. Adding and subtracting is a good place to start. This will allow you to add your family's expenses to figure out if your little brother is laundering money (perhaps literally). Have fun! Common Core Standard: 5.NBT.B.7

You get the general idea of decimal is and what the digits in different places represent (place value). Now you're ready to do something with the decimals. Adding and subtracting is a good place to start. This will allow you to add your family's expenses to figure out if your little brother is laundering money (perhaps literally). Have fun! Common Core Standard: 5.NBT.B.7

You get the general idea of decimal is and what the digits in different places represent (place value). Now you're ready to do something with the decimals. Adding and subtracting is a good place to start. This will allow you to add your family's expenses to figure out if your little brother is laundering money (perhaps literally). Have fun! Common Core Standard: 5.NBT.B.7

In this tutorial, we'll extend our division skills to include decimals! Common Core Standard 5.NBT.B.7

In this tutorial, we'll extend our division skills to include decimals! Common Core Standard 5.NBT.B.9

In this tutorial, we'll extend our division skills to include decimals! Common Core Standard 5.NBT.B.10

In this tutorial, we'll extend our division skills to include decimals! Common Core Standard 5.NBT.B.11

Let's learn to divide any whole number by any other! Common Core Standard: 5.NBT.B.6

Let's learn to divide any whole number by any other! Common Core Standard: 5.NBT.B.7