Leanne is building a model tower tbat needs to be 1.42 meters tall. The model currently is o ly 0.68 meters tall. How many more meters does she need to build in

Question

Leanne is building a model tower that needs to be 1.42 meters tall. How many more meters does she need to build in order to finish the model tower. Draw decimal models to find the difference.

Answer 1

Hi Alicia from Stone Mountain, GA...hope you had a great day at school.

Glad you contacted Wyzant and I am glad to help. So learning about decimal models. A good way to keep in mind, is that decimal models are not too difficult keeping in mind we are counting in groups of 10.

Draw this on your paper so you understand as well.

Let's take a number, we'll say 16 and put it into a decimal model:

   1   6    so in the first column we have 10 x's to signify the ten's place

   x   0    in the second column, we have 6 x's to signify the 6 in the one's

   x   0          place

   x   0    You can make a decimal model by drawing a box with columns

   x   0         of 10 squares,

   x   x

   x   x

   x   x 

   x   x

   x   x

   x   x

 

If we had the number 38, our model would be:

      in the first column, there would be 3 x's and 7 0's

      in the second column, there would be 8 x's and 2 0's

If you drew a box with two columns, each with 10 small boxes on top of each other, color in the 3 boxes in the first column and color in 8 boxes in the second column. When you draw a box with 10 smaller boxes on top of each other, color in the boxes which is equal to the number you are representing.   If you have 3 numbers, like 479, you will have 3 columns of boxes, in the first column you color in 4 of the 10 boxes

              in the second column, you color in 7 of the 10 boxes

        and in the third column, you color in 9 of the 10 boxes

Now we have been working on numbers on the left side of the decimal line

If you have a number like:  35.26, this is how it goes

            in the first column, you color in 3 of the 10 boxes

            in the second column, you color in 5 of the 10 boxes

Draw a thick dark line inbetween the second column and the next column

         The thick dark line represents the decimal point and all the numbers

          on the right side of the decimal line 

       in the next column on the right side of the dark line, color in 2 boxes

                 of the 10 boxes

       and on the second column on the right side of the dark line, color in 

            6 of the 10 boxes

I hope this makes sense.

   The problem asks you to calculate how much more you need to build to complete the tower.

So you will need 3 boxes, each representing the 1.42 meters[I showed you how to do that]  minus  0.68 meters[the amount you have built so far and I showed you how to do that as well] which will equal how much more you have left to build: Your equation looks like this:

        1.42 meters  -  0.68 meters  =   ? meters [you know how to do this]

Let me know if you have other questions. Contact me on Wyzant