Jump to content

Menu

Saxon 87 math problem help needed


Abbeygurl4
 Share

Recommended Posts

My ds is on lesson 74, lesson practice problem "c".

 

C. Eighty is 0.4 of what number?

 

The method they want him to use is :

 

80 = 0.4 x Wn

 

80/0.4 = 0.4 x Wn/0.4 ( I couldn't type it as a fraction)

 

200 = Wn

 

DS's method is :

 

80 = 0.4 of X

 

0.4 = 2/5

 

(80 divided by 2) 5 = 200

 

 

My question is : Is there a reason behind Saxon having him do this problem a specific way or can ds use his method? Ds says that the Saxon method is very confusing to him. I'm not sure what to do.

Link to comment
Share on other sites

My ds is on lesson 74, lesson practice problem "c".

 

C. Eighty is 0.4 of what number?

 

The method they want him to use is :

 

80 = 0.4 x Wn

 

80/0.4 = 0.4 x Wn/0.4 ( I couldn't type it as a fraction)

 

200 = Wn

 

DS's method is :

 

80 = 0.4 of X

 

0.4 = 2/5

 

(80 divided by 2) 5 = 200

 

 

My question is : Is there a reason behind Saxon having him do this problem a specific way or can ds use his method? Ds says that the Saxon method is very confusing to him. I'm not sure what to do.

 

There is no difference - he is doing exactly the same thing. Whether he calls the fraction 0.4 or 2/5 makes no difference.

He should, however, learn to properly write out his procedure, using a variable for the unknown quantity:

80 = 0.4 of X = (2/5) X

80/ (2/5)=X

X=200

Link to comment
Share on other sites

There is no difference - he is doing exactly the same thing. Whether he calls the fraction 0.4 or 2/5 makes no difference.

He should, however, learn to properly write out his procedure, using a variable for the unknown quantity:

80 = 0.4 of X = (2/5) X

80/ (2/5)=X

X=200

 

:iagree:

Link to comment
Share on other sites

There is no difference - he is doing exactly the same thing. Whether he calls the fraction 0.4 or 2/5 makes no difference.

He should, however, learn to properly write out his procedure, using a variable for the unknown quantity:

80 = 0.4 of X = (2/5) X

80/ (2/5)=X

X=200

 

Gotcha! Thank you!

Link to comment
Share on other sites

I would also make sure he knows how to divide by a decimal, since they were clearly wanting him to practice that. 0.4 was easy to convert to a fraction, but what if the problem was "80 is .12345 of what number?" Then he'd want to use the decimal (and long division by .12345 probably isn't real exciting :lol:).

Link to comment
Share on other sites

I would also make sure he knows how to divide by a decimal, since they were clearly wanting him to practice that. 0.4 was easy to convert to a fraction, but what if the problem was "80 is .12345 of what number?" Then he'd want to use the decimal (and long division by .12345 probably isn't real exciting :lol:).

 

Good point, I'll make sure.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...