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You can attend the first session of any of our online or in-person GRE courses absolutely free. Crazy, right? <\/i><\/b>Check out our upcoming courses here<\/i><\/b><\/a>.<\/i><\/b><\/p>\n <\/i><\/b>There are a few math terms that are banned from my GRE classroom. \u201c<\/span>I\u2019m not a math person<\/span><\/a>\u201d is a big one. So is \u201c<\/span>You either know it, or you don\u2019t<\/span><\/a>.\u201d Both of those sentences are untrue\u2014they don\u2019t describe how the human brain really works\u2014and they\u2019re also dangerous.<\/span><\/p>\n The words that we choose are important. If we want to succeed on the GRE, we should talk about our learning in a way that reflects that. And if we want to do GRE Quant problems clearly and methodically, we should also talk about them clearly and methodically. That\u2019s why, in addition to the \u201cdangerous\u201d math terms up there, there are a couple of other \u201cdirty words\u201d that I\u2019ve banned from my classroom. If you cut these words and phrases out of your GRE Quant vocabulary, I promise that you\u2019ll make fewer careless errors, understand problems more clearly, and feel more confident about your solutions. <\/span><\/p>\n Don\u2019t say this: <\/b>\u201cMoved it to the other side of the equation\u201d<\/span><\/p>\n Say this instead: <\/b>\u201cAdded\/subtracted it from both sides\u201d<\/span><\/p>\n Here\u2019s a little math problem where this comes into play:<\/span><\/p>\n If (x \u2013 1)\u00b2<\/span>\u00a0= 256, which of the following could be the value of x?<\/span><\/p>\n (A) 24 Okay, take the square root first\u2014that gives you x-1 = 16. Then, just <\/span>move the -1 to the other side of the equation<\/b>\u2026 aha! 15 is the right answer. Right? Nope. <\/span><\/p>\n The answer is actually -15, and here\u2019s how you get there with confidence, 100% of the time. Say the following to yourself, and write the equations down on your paper.<\/span><\/p>\n Take the square root of both sides<\/span><\/i>. x \u2013 1 = 16 <\/span><\/p>\n Add 1 to both sides.<\/i><\/b> x = 17. <\/span>Okay, that\u2019s not an answer choice. Let\u2019s try the negative square root.<\/span><\/i><\/p>\n x \u2013 1 = -16. <\/span>Add 1 to both sides<\/i><\/b>.<\/span><\/i> x = -16 + 1 = -15. There\u2019s the right answer. <\/span><\/p>\n If you\u2019re doing math in your head, or if you\u2019re working quickly, or if you\u2019re tired, it\u2019s easy to mess this one up. (By the way, never do math in your head on the GRE. Doing math in your head is like eating a dozen donuts by yourself: it seems like a good idea, until you discover the consequences.) The problem is with the \u201cmove the -1 to the other side.\u201d There\u2019s no math operation called \u201cmove it to the other side.\u201d There\u2019s no \u201cmove it to the other side\u201d button on your calculator! You aren\u2019t <\/span>moving<\/span><\/i> anything: you\u2019re either adding the same number to both sides, or subtracting the same number from both sides. In this case, you\u2019re adding 1 to both sides. <\/span><\/p>\n Even if you don\u2019t think you need to work on your arithmetic skills, try banning \u201cmove it to the other side\u201d from your vocabulary. Instead, speak and think in terms of <\/span>doing the same math to both sides<\/span><\/i>. You\u2019ll probably catch yourself almost making mistakes\u2014every time that happens, it means this technique paid off. \u00a0<\/span><\/p>\n Don\u2019t say this: <\/b>\u201cCross-multiplied\u201d<\/span><\/p>\n Say this instead:<\/b> \u201cMultiplied both sides by\u2026\u201d<\/span><\/p>\n \u201cCross-multiplication\u201d is among my ten least favorite phrases in the English language, right along with \u201cpop quiz\u201d and \u201cboiled cabbage.\u201d The problem isn\u2019t with cross-multiplication itself. Rather, it\u2019s with <\/span>knowing when to use it<\/span><\/i>. Cross-multiplication is for one very specific situation: when you have exactly two fractions with an equals sign between them, like this. <\/span><\/p>\n It\u2019s not for problems like this:<\/span><\/p>\n Or this:<\/span><\/p>\n Or this:<\/span><\/p>\n Cross-multiplication isn\u2019t anything special. It\u2019s a combination of techniques that you can use on a lot of different types of problems. However, using a special name for it makes it less clear when you can use it, and what it actually does. That\u2019s where careless errors come from: not clearly thinking through exactly what math you\u2019re trying to do. Say and think through what you\u2019re doing mathematically, instead. <\/span><\/p>\n To solve the first problem, you could <\/span>multiply both sides by 7<\/b>, then <\/span>multiply both sides by 8<\/b>. That\u2019s not cross-multiplication\u2014it\u2019s just doing the same thing to both sides of the equation, twice. <\/span><\/p>\n For the second problem, you can\u2019t do the same thing to both sides, because there\u2019s nothing on the right side. You have to use a different technique. Multiply the top and bottom of the left fraction by 8, and multiply the top and bottom of the right fraction by 5. That gives you a common denominator, so you can add them together. <\/span><\/p>\n To do the third one, you could multiply the two fractions together first. Or, you could multiply both sides of the equation by 4 and then by 7. Take your pick! The fourth equation requires you to combine the techniques from the previous two. None of them involve \u201ccross-multiplication.\u201d If you think about the math you\u2019re actually doing when you cross-multiply, instead of just applying the technique right away, you\u2019ll be better equipped to handle fractions on the GRE.<\/span><\/p>\n This might seem like nit-picking. But I\u2019ve worked with many students who are frustrated with careless mistakes on GRE Quant. Most or all of those careless mistakes, in my experience, are completely avoidable. Often, they come from <\/span>thinking<\/span><\/i> carelessly\u2014for instance, from using a math technique in the wrong way, or on the wrong problem. Going back to the basics and thinking through the <\/span>mathematical steps you\u2019re taking<\/span><\/i> will keep you from doing this, so please give it a try! ?<\/span><\/p>\n See that \u201cSUBSCRIBE\u201d button in the top right corner? Click on it to receive all our GRE blog updates straight to your inbox!<\/i><\/b><\/p>\n Chelsey Cooley<\/a> You can attend the first session of any of our online or in-person GRE courses absolutely free. Crazy, right? Check out our upcoming courses here. There are a few math terms that are banned from my GRE classroom. \u201cI\u2019m not a math person\u201d is a big one. So is \u201cYou either know it, or you […]<\/p>\n","protected":false},"author":127,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15,474284,921840,421,6,7,733451,9,733445],"tags":[1362410],"yst_prominent_words":[],"class_list":["post-10347","post","type-post","status-publish","format-standard","hentry","category-gre-math-algebra","category-current-studiers","category-gre-prep-2","category-gre-quant-2","category-gre-strategies","category-how-to-study","category-life-hacks","category-math-gre-strategies","category-study-tips-2","tag-math-terms"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10347","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/users\/127"}],"replies":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/comments?post=10347"}],"version-history":[{"count":5,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10347\/revisions"}],"predecessor-version":[{"id":10415,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10347\/revisions\/10415"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/media?parent=10347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/categories?post=10347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/tags?post=10347"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/yst_prominent_words?post=10347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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\n<\/span>(B) 15
\n<\/span>(C) -15
\n<\/span>(D) -16
\n<\/span>(E) -17<\/span><\/p>\n![\"Manhattan](\"http:\/\/www.manhattanprep.com\/gre\/wp-content\/uploads\/sites\/19\/2017\/05\/cc-48-image-1.png\")
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\n![\"Chelsey](\"https:\/\/cdn2.manhattanprep.com\/gre\/wp-content\/uploads\/sites\/19\/2015\/11\/chelsey-cooley-150x150.jpg\" "\\"Chelsey")
<\/a> is a Manhattan Prep instructor based in Seattle, Washington.<\/strong>\u00a0<\/em><\/i><\/b>Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master\u2019s degree in linguistics, a 790 on the GMAT, and a perfect 170Q\/170V on the GRE.\u00a0<\/em><\/i>Check out Chelsey\u2019s upcoming GRE prep offerings here<\/a>.<\/em><\/i><\/p>\n","protected":false},"excerpt":{"rendered":"