How to avoid “silly” mistakes in Quants?

You know the concept, the setup, the steps. You have equations ready and a prowess with algebra. You solve the problem and come up with what is certainly the correct answer, yet you quickly find that answer is not one of the answer choices. You, my friend, are in danger of having just committed a careless error or a “silly” mistake. Careless errors are the worst named type of error. Did you really make that mistake because you didn’t care enough? If the CAT were more important to you, your accuracy would increase? That is doubtful. Yet students constantly look at a careless error and respond with a comment like “That was silly. I won’t do that again.” Care about this test as much as you want, telling yourself not to do something again has almost no impact on whether you will do it again or not.But how do you avoid falling in the careless error trap? You can’t learn your way around it. You can’t check every single computation you ever do. The solution is to employ strategies that target your particular brand of careless error. Before we go through what those strategies are, you should have a method for determining where the mistakes are coming from. Not all careless errors are created equal. The best method for pinning down a weakness is to keep an error log. Let’s focus on that final component: What corrective measures will you take. Each type of careless error has its own solution(s), so let’s tackle the top five types. 1. Arithmetic Errors This is the brand of careless errors that most of you will have to overcome when you are studying for the CAT. Arithmetic errors occur when you make mistakes while combining numbers. The equations and strategy may be fine, but at some point you’ll compute 4 * 7 to be 26. This is definitely going to impact your accuracy on problem solving .If you’re seeing this error pop up with small number computations, the first suggestion would be to make flashcards drilling all the basic multiplication tables.You may feel like a fool pulling out cards that said “7 * 6 = ?,” but after a few weeks, you will automatically multiply and divide any number up through 12. This also let me make quick checks to your maths such as: 7 * 6 = 40, right? 40 / 6 = not 7 — Try again 7 * 6 = 42, right? 42 / 6 = 7 For larger numbers, writing is your friend. Don’t be afraid to write out long division and multiplication. It’s better to write more and increase your accuracy. You can also look for ways to make the multiplication easier. For example: 4,634 * 99 = ? Well, 99 = (100-1), which are much easier numbers than 99.Substitute 4,634 * (100 – 1) = 463,400 – 4,634 = 458,766 Check if you have made a mistake on subtraction: 458, 766 + 4,634 = 463,400. The same trick works when multiplying or dividing by something like 5 (5, 50, 500, 0.5 ….) 4,634 * 50 = ? Well, 50 = (100/2), which are again easier numbers. Substitute: 4,634 * (100 / 2) = (463,400 / 2) = 231,700 The trick here is changing numbers into multiples of ten and small numbers so the arithmetic is much easier than it otherwise would be. Practicing with estimation is recommended for two purposes. First, you can sometimes just estimate the answer and avoid arithmetic entirely. Second, you can check that your arithmetic is in the ballpark. If your estimate says the number will be about 1,000, and you calculate a number that’s about 10,000, you can be pretty confident you made a mistake. 2. Algebraic Errors Algebraic errors occur when there are mistakes manipulating the equations. For example, you may be solving “3x + 2z -5y = 54 +3z” and make the mistake of simplifying that to “3x + 5z – 5y = 54. These mistakes can crop up when you’re working with fractions, negatives, variables, exponents, or any number of problem areas. You may not fall prey to this error in all of these areas (or you may fall prey to it in an entirely different area), so see if you can narrow down your error type for a more focused approach. Regardless of where this error happens, however, you can employ a similar fix. The easiest way to overcome algebraic errors is to write down intermediate steps. Take the example from above: 3x + 2z -5y = 54 +3z write: -3z -3z 3x – z – 5y = 54 Because you wrote out what you were doing, it is much harder to accidentally complete the wrong function. These solutions are far more effective in specific circumstances. If you’re often missing a question type in a certain content area, check to see whether you don’t know the content, or whether it’s just your area for algebraic mistakes. One of the biggest content areas which people make algebraic careless errors in is exponents.