Step 2: Start writing in all the values you know, making sure you can cancel top and bottom. Since you have years on top right now, you need to put years on the bottom in the next segment. Keep going, canceling units as you go, until you end up with the unit you want (in this case seconds) on the top. 3 X 365 days X 24 hours X 60 minutes X 60 seconds 1 year 1 day 1 hour 1 minute Step 3: Multiply all the values across the top. Write in scientific notation if it’s a large number. Write units on your answer. 3 x 365 x 24 x 60 x 60 = 9.46 x 107 seconds Step 4: Multiply all the values across the bottom. Write in scientific notation if it’s a large number. Write units on your answer if there are any. In this case everything was cancelled so there are no units. 1 x 1 x 1 x 1 = 1 Step 5: Divide the top number by the bottom number. Remember to include units. 9.46 x 107 seconds / 1 = 9.46 x 107 seconds Step 6: Review your answer to see if it makes sense. 9.46 x 107 is a really big number. Does it make sense for there to be a lot of seconds in three years? YES! If you had gotten a tiny number, then you would need to go back and check for mistakes. In lots of APES problems, you will need to convert both the top and bottom unit. Don’t Just convert the top one first and then the bottom. 50 miles per hour = ? feet per second Example: Step 1: Start with the value and units you are given. In this case there is a unit on top and on bottom. 50 miles 1 hour Step 2: Convert to feet first. 50 miles X 5280 feet 1 hour 1 mile Step 3: Continue the problem by converting hours to seconds. 50 miles X 5280 feet X 1 hour X 1 minute 1 hour 1 mile 60 minutes 60 seconds Step 4: Multiply across the top and bottom. Divide the top by the bottom. Be sure to include units on each step. Use scientific notation for large numbers.
Step 2: Start writing in all the values you know, making sure you can cancel top and bottom. Since you have years on top right now, you need to put years on the bottom in the next segment. Keep going, canceling units as you go, until you end up with the unit you want (in this case seconds) on the top. 3 X 365 days X 24 hours X 60 minutes X 60 seconds 1 year 1 day 1 hour 1 minute Step 3: Multiply all the values across the top. Write in scientific notation if it’s a large number. Write units on your answer. 3 x 365 x 24 x 60 x 60 = 9.46 x 107 seconds Step 4: Multiply all the values across the bottom. Write in scientific notation if it’s a large number. Write units on your answer if there are any. In this case everything was cancelled so there are no units. 1 x 1 x 1 x 1 = 1 Step 5: Divide the top number by the bottom number. Remember to include units. 9.46 x 107 seconds / 1 = 9.46 x 107 seconds Step 6: Review your answer to see if it makes sense. 9.46 x 107 is a really big number. Does it make sense for there to be a lot of seconds in three years? YES! If you had gotten a tiny number, then you would need to go back and check for mistakes. In lots of APES problems, you will need to convert both the top and bottom unit. Don’t Just convert the top one first and then the bottom. Example: 50 miles per hour = ? feet per second Step 1: Start with the value and units you are given. In this case there is a unit on top and on bottom. 50 miles 1 hour Step 2: Convert to feet first. 50 miles X 5280 feet 1 hour 1 mile Step 3: Continue the problem by converting hours to seconds. 50 miles X 5280 feet X 1 hour X 1 minute 1 hour 1 mile 60 minutes 60 seconds Step 4: Multiply across the top and bottom. Divide the top by the bottom. Be sure to include units on each step. Use scientific notation for large numbers.