Math Review of Applications of Percents

Overview Percents are based on the decimal system and have many useful applications in business, sales, and finance. Other applications of percents include percent increase and decrease. Estimating Percentages Many of the most useful applications of percents involve estimating and calculating percentages for sales tax and tips at a restaurant. Suppose the sales tax is […]

Science Review of Rainbows

Overview Rainbows, glories, fogbows, and glassbows are all related phenomena caused by the nature of light. Each color is created by light hitting raindrops or beads of glass. They have fascinated people  for millennia, including Aristotle and Sir Isaac Newton. The Science of Rainbows Rainbows are phenomena that are created whenever the conditions are right […]

Biology Review of Combating Global Warming

Overview Global warming refers to the rise in the average temperature of the climate system of the Earth. Some of the energy has resulted in the increase in ocean temperature. Some glaciers and icebergs have already melted, resulting in widespread change in habitat for many Arctic species. Scientists and politicians have proposed ways to combat […]

English Review: Spelling

Overview Spelling errors are some of the most common types of errors to find when editing an essay. Some words are often misspelled, while other words are commonly confused. Strategies to fix spelling errors include looking up the correct spelling, using mnemonics to remember usage, and underlining words to check later. Although the spell-check feature in […]

Biology Review of the Ozone Hole and Global Warming

Overview Human activity has affected the biosphere on Earth as the population has grown to over 7 billion. Some of the most troubling effects include changes to the ozone layer and global warming. The Stratosphere The stratosphere in Earth’s atmosphere is between 10 and 50 km above the surface. It has an inverted temperature, so […]

English Review: Modifiers

Overview Modifiers are words, such as adjectives or adverbs, or phrases, such as prepositional phrases, that add description to other words in a sentence.  Check to see if they are used in the correct form and location when editing an essay. Adverb or Adjective? Adverbs and adjectives are similar modifying words that take different forms […]

English Review: Verbs

Overview Verbs carry the action in sentences. Sometimes, however, it is difficult to choose the correct form of the verb to use when number, order, and tense are in question. Some strategies for correcting verb forms include editing phrases temporarily, rewriting questions, checking indefinite pronouns, and noting verb tenses. Cross out Prepositional Phrases Prepositions are […]

Math Review of Compound Inequalities

Overview Compound inequalities are similar to compound statements, as they are two simple inequalities joined by conjunctions. Suppose it were true that a variable x was between 2 and 9. A sentence would be written combining the statements “x is greater than 2” AND “x is less than 9.” Compound Statements Compound statements are common […]

Math Review of Inequalities with More than One Step

Overview If an inequality contains more than one operation, it will take more than one step to solve it. Suppose that in order to solve an inequality, both multiplication and addition statements need to be undone by using the multiplicative and additive inverses. As with other inequalities that take one step, the variable will have […]

Biology Review of Cones and Flowers

Overview Plants that reproduce by seed include cone-bearing plants and flowering plants. They can live in many different environments, because seeds store food separately for the plant embryo, to be used when the plant has the right conditions to sprout. Formation of Seeds Seed structure is similar for both cone-bearing plants and flowering plants. The […]