Step by step
The question
Question: 3 more than 5 times a number is 28.
Find the number.
1 Find what we know
What do we know?
3 more than 5 times a number is 28.
What do we want?
The number.
2 Name the unknown
We don't know the number.
So we call it x.
3 Write the equation
Change the words to math, one part at a time.
We start with 5 times a number, then add 3.
So the equation is 5x + 3 = 28.
Now we solve it.
We want x by itself.
Two things are stuck to x: times 5 and + 3.
The + 3 is on the outside, so it comes off first.
Then the times 5.
4 Remove the + 3
To remove + 3, we take away 3.
We do it on both sides, so they stay equal.
+ 3 and − 3 make zero.
Cross them out.
28 − 3 = 25.
Now we have 5x = 25.
5 Remove the 5
5x means 5 times x.
We want just x.
To remove times 5, we divide by 5.
We do it on both sides, so they stay equal.
5 divided by 5 is 1.
So just x is left.
25 divided by 5 is 5.
So x = 5!
6 Answer the question
The number is 5.
7 Check
Let's check in the story.
Put 5 in the story: 3 more than 5 times 5.
It makes 28, like the story says.
So the answer is right!
Let's look back.
First: find what we know.
Then: name the unknown.
Then: write the equation.
Then: solve it.
Then: answer the question.
Last: check.