Question

Carpentry:How many shelves,each 240 cm long,can be cut from a board that is 7.20 m in length?Find the length of the board remaining after the shelves are cut.

Answer 1

First, notice that they are asking you a problem with two different units of measure... each shelf is 240 cm long, but the board's length is measured in meters.

Answer 2

So, if I asked you an easier problem... what is the length of the board left over after you cut shelves 2 feet long from a 5-foot board?

Now you can get the idea of the problem without doing the unit conversions. Then we'll do the actual problem with the unit conversions... it will seem easy then :)

Answer 3

it will be 3 feet board

Answer 4

well, if you cut a single 2-foot shelf, then yes, you have 3 feet left.. but maybe you should cut that 3-foot piece into another 2-foot shelf, leaving a 1-foot piece leftover.

So a 5-foot board can be DIVIDED (key word) into two 2-foot pieces, with a 1-foot REMAINDER (key word) left over.

5 divided by 2 is equal to 2 with a remainder of 1.

Answer 5

So in your actual problem, you can divide the whole board length 7.20 m, by the length of each shelf, 240 cm.

But first, you should express the board length in terms of "cm" so you have a common unit of measure.

7.20 m = 7,200 cm

7,200 cm / 240 cm = ?

Answer 6

it will 30 cm

Answer 7

close... think of what you just solved for... you said, I have 7200 cm of board, and I am going to start cutting off pieces for shelf that are 240 cm long... so 7200/24 will be 30 shelves, not 30 cm.

right math, but you got mixed up on interpreting your answer.

Is there any board left over? A remainder?

Answer 8

no

Answer 9

ok
thanks i got my answer.

Answer 10

great :) It's just division with remainders, and the only thing making it complicated is that they mixed the units... first, get the units all the same, then do the math, then interpret the results to make sure you are answering the actual question... don't let your calculator confuse you :) It will do the math, but you need to think about how to phrase the answer itself :)

Good work though :) Keep it up :)