Help Me with Math

This is one of my weak points in math when it comes to feet, inches, etc.

A farmer wants to build a rectangular pen to hold cattle. If the dimensions of the pen are to be 24 ft. 6 in., what is the complete amount of fencing needed to build the pen?

 

what grade are you in?

 

None. Last school year was my last year at the high school.

This is a GED packet.

 

Use an old calculator to subtract 1.120 from 1.254, then turn it upside down.

 

Math just hates me. There are also time questions.

John needs to work a total of 3 hours and 20 minutes in order to pay back his grandfather for a loan. If John has already worked 1 hour and 45 minutes, how much longer does he need to work to finish paying off the loan?

 

Did you do it?

 

No, I can't subtract 45 from 20.

 

No, I meant my thing.

 

1 hour 35 minutes longer.

 

Yeah, I looked at the answers since it's just a practice, but I don't know what they did.

If I don't know how to do it, I won't learn.

I mean, there's an introduction showing you what to do, but they only show the addition side of it.

 

60 minutes in an hour:
3 hours 20 minutes
200 minutes

Worked 1 hour 45 minutes
105 minutes

200-105= 95

1 hour equal 60 minutes

95-60=35

1 hour 35 minutes remains.

I'll add in more steps if you're confused, I skipped the simplistic steps I'd assume you'd be able to follow just fine.

 

There's 60 minutes in an hour.

3 hours and 20 minutes is the same as 200 minutes. (3 x 60 = 180, 180 + 20 = 200)
1 hour and 45 minutes is the same as 105 minutes. (60 + 45 = 105)

200 - 105 = 95 minutes.

95 minutes = 1 hour 35 minutes. (95 - 60 [one hour] = 35)

EDIT: got beat to it.

 

Here's what I did, which was, of course, wrong:

320 - 145.

Borrow one from the two.

10 - 5 = 5

Borrow one from the three.

11 - 4 = 7

2 - 1 = 1

320 - 145 = 175

The one and the five are right, but not the seven.

 

You were saying 3 hours and 20 minutes is the same as 320 minutes, which is wrong as there are only 60 minutes in an hour not 100, so you have to convert from hours to minutes first before you subtract them.

 

Alright, so here's my next one.

It will take Jennifer 2 hours and 15 minutes to finish running in a marathon. If she has already run for 1 hour and 27 minutes, how much longer does she need to run to complete the marathon?

2 hours and 15 minutes = 135 minutes (2 x 60 = 120 + 15 = 135)
1 hour and 27 minutes = 87 minutes (1 x 60 = 60 + 27 = 87)

135 - 87 = 48

However, I can't subtract 60 from 48, but I can subtract 48 from 60, which equals 12.

It would be 1 hour and 12 minutes?

 

It's 48 minutes. You were right first time.

 

No, that would be 48 minutes. You only subtract 60 if it is larger than 60, and for every 60 minutes you subtract, you change to 1 hour. I'm probably not explaining this well.

 

You explained it perfectly fine, I just didn't know you only subtracted 60 from a number equal to it or higher than it.

So 1 hour and 48 minutes it is.

 

The answer is 48 minutes.

There is no need to subtract 60 from 48.
The questions asks you how long Jennifer needs to run to finish and the answer is 48 minutes.
You worked out that the total time to finish the marathon takes 135 minutes.
If Jennifer has already ran 87 minutes, you need to calculate how many more minutes she needs to run to make 135.

87 + (your answer which is 48) = 135