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Elapsed Time Problems

Added Aug 02, 2017 •

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How to solve math story problems involving elapsed time.

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hello everyone this is mr. Smith and I'm going to spend a little time today talking with you about you elapsed time problems this is something that third graders typically have a very difficult time with so I'd like to just go through some of the steps that we cover here in class solving an elapsed time problem so that you can use those same steps to help your child practice at home and when they're doing homework problems now any time problem  here's a question that would look something like that it would give a starting time like we start class at 2:27 an ending time and we end at 3:15 and then the elapsed time problem ask how much time has passed from the starting time for the ending time the way that we show students to solve a problem like this is by making what's called an open number line and you can see I drew a number line across the page beer and on one end of the number line hoop down here there we go on the starting end of the number line I put the starting time which is 227 turn on the ending on side of the number line the ending time which is 3:15 now one of the things that we've talked a lot about is reference .4 oclock and hear the cloth that we used in class and we divided it up into some various reference points for example we divided the clock up quarters and talked about how a quarter of an hour is 15 minutes so every quarter that we shaded a different color is something that we could use a reference point to count by 15s Around the Clock we also talked about half hours and hours as reference points that are easy to count night as well as five minute intervals Around the Clock when we count the numbers and count by 5 so what we want to do when in a lot of time problem is we Play Take This open number line that we made and divided up into intervals that are easier for students to count by where's the next step of the problem and you can see that the first interval that I did was I counted by one minute intervals from together from to 27 to 2:30 and that was three minute jump so we have one two three and that takes us to 2:30 once we get to 30 it's an easy 30 minute jump from 2:30 to 3 and you can see up above that jump I wrote the 32 represent that jump with 30 minutes and then that takes us almost to the end where at 3 now and we were trying to get to 315 so again we we would remember that a 15-minute jump is a quarter of the clock and that that's an easy jump to make so from 3 to 3:15 is another 15 min so now we taking this whole elapsed time problems and across the top of our number line divided it up into some small jump that make it can you count from the beginning or starting time to the ending time we just go back then and add up our minute we have our three one minute Jump Plus are 30 jump and are 15 minutes jump so 30 + 15 I had my large numbers first to get 45 and then add on the 346-4740 and you can see how this diagram makes it easier to find that this elapsed time problem had a total time of 48 minutes now this works with some longer problems as well problems that spanned over the course of more than one hour and we just take those reference point that we came up with on our clock and draw it out on the number line and divided up into smaller segments that are easier for students to count play in Jump by and that is always solve any elapsed time problem

Uploaded by Steve Smith.

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Elapsed Time Problems

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