Using the dimensional analysis method Includes examples from “fun with dimensional analysis”, “dimensional analysis”, and “using the international system” handouts

How many seconds are in a day? (from “Fun with Dimensional Analysis”) You will write the unit that you don’t yet know LAST!!! Start by writing the unit that you know: 1 day Next, write a conversion fraction, with the unit that you want to cancel out (day) at the bottom, and an equal value (24 hours (= 1 day)) at the top. THE VALUE AT THE TOP SHOULD BRING YOU CLOSER TO YOUR DESIRED ANSWER Cancel units that appear at the top of one fraction and the bottom of the next. YOU WILL REPEAT THIS PROCESS UNTIL YOU HAVE ARRIVED AT THE UNIT (seconds, in this case) THAT YOU WANT TO FIND OUT

Convert 5 years into seconds (“Dim. An.” 2 ques. wksht) You will write the unit that you don’t yet know LAST!!! Start by writing the unit that you know: 5 years Next, write a conversion fraction, with the unit that you want to cancel out (yrs) at the bottom, and an equal value (365 days (= 1 yr)) at the top. THE VALUE AT THE TOP SHOULD BRING YOU CLOSER TO YOUR DESIRED ANSWER Cancel units that appear at the top of one fraction and the bottom of the next. YOU WILL REPEAT THIS PROCESS UNTIL YOU HAVE ARRIVED AT THE UNIT (seconds, in this case) THAT YOU WANT TO FIND OUT

Convert 25.4 seconds into years (“Dim. An.” 2 ques. Wksht – ques. 2) You will write the unit that you don’t yet know LAST!!! Start by writing the unit that you know: 25.4 seconds Next, write a conversion fraction, with the unit that you want to cancel out (60 sec) at the bottom, and an equal value (1 min (= 60 sec)) at the top. THE VALUE AT THE TOP SHOULD BRING YOU CLOSER TO YOUR DESIRED ANSWER Cancel units that appear at the top of one fraction and the bottom of the next. YOU WILL REPEAT THIS PROCESS UNTIL YOU HAVE ARRIVED AT THE UNIT (years, in this case) THAT YOU WANT TO FIND OUT. To calculate answer, be sure to divide by denominators as you go!!!

“USING THE INTERNATIONAL SYSTEM” PACKET – “YOUR TURN” PROBLEMS 1-5 WHEN CONVERTING FROM ONE METRIC UNIT TO ANOTHER, CONVERT TO THE BASIC UNIT FIRST!!! OR OR

Now, try converting 1 km to mm WHEN CONVERTING FROM ONE METRIC UNIT TO ANOTHER, CONVERT TO THE BASIC UNIT FIRST!!! or

Are you stuck? Always do this: 1. start with the unit that is accompanied by a number. 2. write this unit as a fraction (put it over 1) 3. multiply it by another fraction. You will write the same unit that’s at the top of the first fraction at the bottom of the second fraction. At the top of the 2nd fraction, write a unit that is equal to the bottom unit. 4. Cancel the unit at the top of the 1st fraction, and the bottom of the 2nd fraction. 5. Look at the unit at the top of the rightmost fraction. Is it the same unit as the unit that you’re trying to solve for? A. If it is, then finish the math (mult. or divide), and you’re done! B. If it’s not, then repeat steps 3-5A. until it is – then you’re done!