# Math homework help -fractions 'of' and fraction word problems

Math homework help home

Students send me scans (or cell phone pictures) of their math homework with their own answers written down. I review and rectify mistakes, if any so that they have all correct answers by the time they turn them in to their school teachers. I also make efforts to explain the concepts/steps briefly.

Note that this is a paid service but costs significantly less than live tutoring sessions. Here are a few examples from pre algebra to show what I receive and what I send back. You can use these solutions as solved examples to learn on your own. Don't miss out on the tips and tricks, if any.

#### Find a fraction of a number What I received What I sent back click on pictures to enlarge
Tip: The word 'of' usually translates to multiplication. So,
35 of 15
= 35 × 15
= 35 × 151
= 351 × 1531
= 9
You can also use this idea ('of' means multiplication) to solve percentage problems.

Another way to think about this is to divide 15 into 5 (the denominator) groups of equal size - so each group has 3 - and then combining 3 (the numerator) of those groups.
In other words, this is the same as doing
15 ÷ 5 × 3

#### Fraction word problems What I received What I sent back click on pictures to enlarge
Tip: It helps to remember the decimal equivalent of some common fractions. Look at #1 for example.
The denominators - 2, 10 and 5 are super friendly. So, you could just do this problem (and many more like this one) mentally. Here's how.
2 12 = 2.5
2 310 = 2.3
3 25 = 3.4
Doing 2.5 + 2.3 + 3.4 is as easy as doing 25 + 23 + 34. The answer is 82 (I mean 8.2).
Who doesn't know that .2 as a fraction is 210,
that simplifies to 15
Therefore, the answer is 8 15

Can you apply the same concept to solve #8?
Hint: 34 = 0.75