How to Solve Number Word Problems Part 4
This is the fourth part and the conclusion to the Number Word Problem Series. In the introduction to this series, we have learned How to Solve Number Problems Mentally. In Part 1 and Part 2, we have discussed the basic number word problems, and in Part 3, we have learned how to solve word problems about consecutive numbers.
In this post, we discuss about more complicated problems especially problems that involve fractions. We have already discussed 9 problems in the previous parts of this series, so, we now solve the 10th problem.
Problem 10
There are consecutive numbers. The sum of the second and the fourth number is
. What is the largest number?
Scratch Work
Since we have five consecutive numbers, if we let be the smallest, then the other numbers are
,
,
, and
.
Now, the second number is and the fourth is
. Their sum is
. And that’s where we get our equation.
Solution
Let ,
,
,
and
be the five consecutive numbers.
Second Number:
Fourth Number:
Second Number + Fourth Number =
Subtracting 4 from both sides,
So, the five consecutive numbers are ,
,
,
and
The largest among them is .
Check: Yes, they are consecutive numbers and .
Problem 11
A number added to of itself is equal to
. What is the number?
Scratch Work
If that number is equal to , then
of that number is
or
. Therefore, if the number is
, it’s one fourth is
. Now, if we add
and
, the sum is 80. That is where we get our equation.
Solution
Let be the number and a fourth of it as
To get rid of the fraction, we multiply everything by . This gives us
Check: of
is
. Now,
. This means that we are correct.
Problem 12
One number exceeds the other by . One third the larger subtracted by one one half the smaller is equal to
. What are the numbers?
Scratch Work
One number exceeds the other by 22 means that the other number is 22 more than the smaller. So, if we let be the smaller number, the larger number is
.
Now, we will subtract one-third by one fourth of
. The difference will be
. In equation form we have
.
Solution
Let be the smaller number and
be the larger.
The least common multiple of the denominators of the fraction (3 and 2) is , so we multiply everything with
to eliminate the fractional parts.
By the distributive property, we have
Multiplying both sides by gives us
which is the smaller number. The larger number is
.
Check: .
That’s it! I wanted to discuss more number problems, but we have other problems to discuss, so I’ll leave this topic for now. In the next post, we will be solving problems about age.