How do you solve: 4/7 of a group of children are boys. If there are 18 more boys than girls, how many children are there altogether

Question

this is a question from my fith grade math workbook that I do not understand

Answer 1

Since this is fifth grade work, let's start by saying that the smallest number of children would be 7 (because 4/7 of them are boys, and that would be four boys--no fractions allowed!).

 

What is it's 4 boys & 3 girls?  Then the number of boys would not be 18 more than the number of girls.

 

So let's try 14 children...8 boys, 6 girls...but difference in boycount and girlcount is only two.

 

I guess we'll have to jump ahead...let's try 18 times 7, or 126 as total--4/7 of that is 72 boys, and 3/7 of that is 54 girls.

 

That's it: 126 children.