In one sentence, describe what the following article is about: A periodic inventory method means that inventory is calculated at regular intervals. For example, you may count inventory monthly, quarterly or semi-annually. The formula is straightforward in this case: (Beginning Inventory + Purchases Ending Inventory = COGS). For example, suppose you have a business selling toasters. At the beginning of October, 2015, you had $900 of inventory on hand. During the month of October, 2015, you purchased $2,700 of inventory. Your inventory count at the end of the month showed that you had $600 of inventory left. Calculate your COGS with the equation $900+$2,700$600=$3,000{\displaystyle \$900+\$2,700-\$600=\$3,000}. If you do physical inventory monthly, then you always know the beginning and ending inventory for the monthly accounting period. If you do physical inventory less often, such as quarterly, then during the months in-between your physical counts, you will have to estimate the value of the ending inventory using the methods described above. You use this type of method if you keep track of inventory on an item-by-item basis. For example, if you are a retail store that scans barcodes with point-of-sale scanners, then you are keeping track of inventory in real time. If you are keeping track of changing inventory on an item-by-item basis, then when calculating the ending value of the inventory, you have to make some assumptions about which items in inventory were used first during the accounting period. These assumptions are designed to help you account for changes in the cost of items in inventory. The assumptions are known as the First-In-First-Out (FIFO), the Last-In-First-Out (LIFO) method and the Average cost method. Suppose you have a business selling dog collars online. You get all of your dog collars from one vendor. In the middle of November, 2015, your vendor increased the cost of one dog collar from $1.00 to $1.50. Using the FIFO method, you will assume that you sold the older $1.00 dog collars before the newer $1.50 collars. Determine your beginning inventory. At the beginning of November, 2015, you had 50 dog collars on hand, all of which cost you $1.00 each. Your beginning inventory value was therefore $50 (50$1.00=$50.00){\displaystyle (50*\$1.00=\$50.00)}. Calculate your total purchases. During November, 2015, you purchased 100 dog collars: 60 at $1.00 each and 40 at $1.50 each. Your total purchases equal (60$1.00)+(40$1.50)=$120{\displaystyle (60*\$1.00)+(40*\$1.50)=\$120}. Calculate your total goods available for sale. This is your beginning inventory ($50) plus your purchases ($120), for a total of $170. Since you keep perpetual inventory, you know that of this $170 in inventory, 110 units were purchased for $1.00 each ($110), and 40 units were purchased for $1.50 each ($60). You sell 100 dog collars in November, 2015. Using the FIFO method, assume you sold the oldest inventory first. You have 110 units of the $1.00 dog collars on hand. So you assume that all 100 dog collars you sold in November were the $1.00 units. Your COGS for November, 2015 is 100$1.00=$100{\displaystyle 100*\$1.00=\$100}. You still have 10 units remaining of the $1.00 collars. You will need this information next month when you calculate COGS using FIFO. Using the same example, suppose you sell the newest collars first. Assume you sold 100 dog collars in November, 2015. Then, according to LIFO, you sold 40 units that cost you $1.50 each and 60 units that cost you $1.00 each. Your COGS is (40$1.50)+(60$1.00)=$120{\displaystyle (40*\$1.50)+(60*\$1.00)=\$120}. With this method, you find the average of the beginning inventory costs and the purchase made during the month. First calculate the cost per unit. Then multiply this by the number of units on hand at the end of the accounting period. Use this calculation to determine both the COGS and the ending inventory balance. Calculate the average cost per unit with the formula (Beginning Inventory + Purchases in dollars) / (Beginning Inventory + Purchases in units) Using the example above, the cost per unit is $1.13: ($50+$120)/(50+100)=$1.13{\displaystyle (\$50+\$120)/(50+100)=\$1.13}. In the example above, you started with 50 units. During the month, you purchased 100 units for a total of 150 available units to sell. Then you sold 100 units, leaving you with 50 units on hand at the end of the month. Calculate COGS by multiplying the average cost per unit with the total units sold. $1.13100=$113{\displaystyle \$1.13*100=\$113} COGS = $113. Calculate the ending inventory by multiplying the average cost per unit with the number of units left on hand at the end of the month. $1.1350=$56.50{\displaystyle \$1.13*50=\$56.50} Ending inventory = $56.50.
Summary: Calculate the cost of goods sold (COGS) if using a periodic inventory method. Calculate the COGS if using a perpetual inventory method. Calculate COGS using the FIFO method. Calculate COGS using LIFO. Calculate COGS using the Average Cost method.

In one sentence, describe what the following article is about: The following terms will be used throughout the examples, and are common in problems involving algebraic fractions: Numerator: The top part of a fraction (ie. (x+5)/(2x+3)). Denominator: The bottom part of the fraction (ie. (x+5)/(2x+3)). Common Denominator: This is a number that you can divide out of both the top and bottom of a fraction. For example, in the fraction 3/9, the common denominator is 3, since both numbers can be divided by 3. Factor: One number that multiples to make another. For example, the factors of 15 are 1, 3, 5, and 15. The factors of 4 are 1, 2, and 4. Simplified Equation: This involves removing all common factors and grouping similar variables together (5x + x = 6x) until you have the most basic form of a fraction, equation, or problem. If you cannot do anything more to the fraction, it is simplified. These are the exact same steps you will take to solve algebraic fractions. Take the example, 15/35. In order to simplify a fraction, we need to find a common denominator. In this case, both numbers can be divided by five, so you can remove the 5 from the fraction: 15 5 * 335 5 * 7 Now you can cross out like terms. In this case you can cross out the two fives, leaving your simplified answer, 3/7. In the previous example, you could easily remove the 5 from 15, and the same principle applies to more complex expressions like, 15x 5. Find a factor that both numbers have in common. Here, the answer is 5, since you can divide both 15x and -5 by the number five. Like before, remove the common factor and multiply it by what is "left."15x 5 = 5 * (3x 1) To check your work, simply multiply the five back into the new expression you will end up with the same numbers you started with. The same principle used in common fractions works for algebraic ones as well. This is the easiest way to simplify fractions while you work. Take the fraction: (x+2)(x-3)(x+2)(x+10) Notice how the term (x+2) is common in both the numerator (top) and denominator (bottom). As such, you can remove it to simplify the algebraic fraction, just like you removed the 5 from 15/35: (x+2)(x-3) (x-3)(x+2)(x+10) (x+10) This leaves us with our final answer: (x-3)/(x+10)
Summary:
Know the vocabulary for algebraic fractions. Review how to solve simple fractions. Remove factors from algebraic expressions just like normal numbers. Know you can remove complex terms just like simple ones.