Case Interview Math: Instantly Reduce Your Errors by 80%

if you struggle with case interview math and find yourself making at least one math error every case interview no matter how slowly or carefully you do the math then this video is for you a single math mistake on a Consulting case interview could be the difference between getting rejected and Landing a Consulting offer in this video we'll share with you five case interview math strategies that will collectively reduce your math Mistakes by eighty percent or more out of the hundreds of people I've interviewed as a former band manager and interviewer the fifth strategy that I'll share with you is one that I have only seen a few candidates use so make sure that you watch until the end the first case interview math strategy is to Use the distributive property to make mental math multiplication easier let's take a look at an example what is 12 times 24 while you could write this out and just multiply 12 by 24 it's actually easier to use the distributive property to rewrite this as 10 plus 2 times 24. 10 times 24 is 240 and 2 times 24 is 48. adding 240 and 48 we get our answer of 288 let's look at another example suppose we are multiplying 303 by 60. again we can make the math Easier by rewriting this as 60 times 300 plus 3. c times 300 is 18 000 and 60 times 3 is 180. adding eighteen thousand and 180 we get our answer of eighteen thousand one hundred and eighty the second case interview math strategy is to round numbers to make the initial calculations easier and then subtract or add what was rounded to get the exact answer suppose we are multiplying 199 by 35. we can rewrite this as 35 times 200 minus one thirty five times two hundred is seven thousand and thirty five times one is thirty-five subtracting 35 from seven thousand we get our answer of 6965. let's look at another example what is 490 times 22 we can rewrite this as 22 times 500 minus 10. 22 times 500 is 20 times 500 plus two times five hundred or ten thousand plus one thousand which equals eleven thousand twenty two times ten is 220. subtracting 220 from eleven thousand we get our answer of ten thousand seven hundred and eighty if you're finding this video helpful please take three seconds to give this video a like And subscribe to the channel so that you don't miss any of our Consulting case interview content the third case interview math strategy is to use factors of numbers to break down an operation into several smaller and more manageable steps suppose you are multiplying 115 by 12. instead of just straight up multiplying these two numbers you can rewrite this as 115 times 6 times 2. 115 times 6 is 690 and 690 times 2 is 1 380 our final answer let's look at another example what is 4560 divided by 24. again instead of just dividing once we can break up 24 into its factors we can rewrite this as 4560 divided by 2 divided by 2 again divided by 2 for a third time and then divided by three therefore 4560 divided by 2 equals 2280 divided by 2 again equals 1140 and divided by two for a third time equals 570. 570 divided by three equals 190 our final answer the fourth case interview math strategy can be used when multiplying a number with a percentage you can switch or reverse the percentages to make the calculation easier suppose you are trying to find 32 percent of 25. looking at this the answer doesn't come to mind immediately however when we rewrite this as 25 of 32 the answer is clearly 8. let's take a look at another example what is 68 of 50. rewriting this as 50 of 68 we easily see that the answer is 34. and finally this Fifth and last case interview math strategy will prevent you from having too many zeros or too few zeros in your final answer this is by far the most common math mistake that candidates make the key to never making this type of mistake is to multiply units instead of numbers what do we mean by this we can simplify how we write thousands millions and billions by using the letters k m and b for example we can rewrite seventeen thousand as 17K 140 million is 140 M and 8 billion 100 million as 8.1 B when doing math all we need to do is multiply or divide the numbers multiply or divide the letters and then put the two together to get our final answer the only thing you need to remember is that K times k equals m m times k equals b m divided by k equals k B divided by m equals K and B divided by k equals m let me show you just how easy this can make your math let's work through an example together we have sold 12 000 cars at a price of eighteen thousand dollars how much revenue is that to solve this efficiently let's rewrite twelve thousand as 12K and eighteen thousand is 18K we are now multiplying 12K by 18K let's first multiply 12 by 18 to get 216. we then multiply K by K to get M and putting these two together our answer is 216 million dollars as you can see multiplying units makes things much simpler let's look at another example suppose we have 1 billion 680 million in Revenue across 120 000 customers what is the average spend per customer to solve this efficiently let's rewrite one billion 680 million as 1 680 M and 120 000 as 120 k we are now dividing 1 680m by 120k let's first divide 1680 by 120 to get 14. we then divide M by K to get K putting these two together our answer is fourteen thousand dollars without simplifying their original numbers and writing them in terms of K's and M's I'd almost guarantee you that about half of all candidates would miss or have too many zeros in their answer now you will never make a math mistake in which you miss a zero or have too many zeros with these five case interview math strategies you should expect to see an 80 or more reduction in the number of math errors you make if you found this video helpful we have another video that has 20 more case interview tips you can apply to instantly improve your case interview performance I've linked the video in the description below I have one last important message for you if you're looking for a step-by-step shortcut to learn case interviews quickly check our comprehensive case interview course and books links are in the video description we teach the most robust effective case interview strategies in the least time consuming way to save you hundreds of hours of prep time and help you land multiple consulting job offers

Channel: Hacking the Case Interview

Views: 6,386

Keywords: hacking the case interview, case interview math, case interview, case interview mental math, case interview math strategies, case interview math tips, case interview tips

Id: mD9mseCYub0

Length: 7min 27sec (447 seconds)

Published: Thu Sep 14 2023