This father can’t figure this out

Uzzle

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Hi. I am trying to figure out how to explain to my son why the answer is C to question 13 in the attached picture. It is 4th grade math but I can’t figure it out. Someone please help me.
 

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To the left of the boxes is a 3. So you know it's 3 times something.

Above the box you have 100, 40, and 8. These add to 148.

Thus the problem is 3 x 148.

-Dan
 
Here's the explanation: they are wrong. The answer is (d).

The diagram represents a bar with length 100 + 40 + 8 = 148 and height 3, so its area is 3*148.

It is not 108.
 
Here's the explanation: they are wrong. The answer is (d).

The diagram represents a bar with length 100 + 40 + 8 = 148 and height 3, so its area is 3*148.

It is not 108.
I’m not sure if the picture shows up clear enough so I’ll type it out. The teacher said the question is: Zach made this model to find the product of a 3-digit number and a 1-digit number. Which multiplication sentence represents Zach’s model? Does that change anything? Thank you.
 
I’m not sure if the picture shows up clear enough so I’ll type it out. The teacher said the question is: Zach made this model to find the product of a 3-digit number and a 1-digit number. Which multiplication sentence represents Zach’s model? Does that change anything? Thank you.
Absolutely not. The answer is 444
Dr Peterson said it extremely nicely talking about area.
If that wasn't helpful then I will talk about the distributive law.
3*(148) = 3*( 100 + 40 + 8) = 3*100 + 3*40 + 3*8 = 300 + 120 + 24 = 420 + 24 = 444.
I use this method ALL the time to multiply in my head.
 
Thank you everyone. I thought it was but figured the teacher knows. Again thank you everyone.
 
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