How to add fractions - SSAT Middle Level Quantitative

Start by solving for the term in parenthesis. We will need to find the least common denominator in order to add the fractions. Since 6 can be multiplied by 2 to get 12, 12 must be the least common denominator.

Convert the fractions so that they share a denominator of 12.

Add the fractions in parenthesis.

Multiply.

You can then simplify the fraction be removing 12 from both the numerator and denominator.

Add the numerators and leave the denominators alone:

Answer:

Subtract the numerators and leave the denominators alone:

Answer:

Because the two fractions have the same denominator, simply add the numerators and leave the denominator as is:

Answer:

Seven tenths is equal to 0.7; seventeen hundredths is equal to 0.17. Add them, rewriting 0.7 as 0.70:

Since , express each fraction as its equivalent in fourteenths, and add the numerators, as follows:

Sixty-seven tenths, sixty-seven hundredths, and sixty-seven ten-thousandths can be rewritten as 6.7, 0.67, and 0.0067, respectively. Add, appending zeroes at the end of each number as needed:

I think the easiest way to do this problem is to make a common denominator. 4 is the smallest common denominator.

is equivalent to .

When you add and you get .

reduces to and is equivalent to .

First, we need to find a common denominator. In this case, we can convert both denominators to .

Now we can add the numerators.

Both the numerator and denominator are divisible by , so we can simplify.

Add the fractions by writing each with the lowest common denominator, which is .

Add the integers:

Now add the two sums:

The sum of two numbers of unlike sign is the difference of their absolute values, with the sign of the "dominant" number (the positive number here) affixed:

Subtract vertically by aligning the decimal points, making sure you append the 3.2 with a placeholder zero:

This is the correct choice.

When adding fractions, both denominators must be the same. A quick and easy way to do this is to multiply the numerator and the denominator of each fraction by the other fraction's denominator:

and

The is multiplied by 6 on both ends because the denominator of is 6. Likewise, is multiplied by 3 on both ends because the denominator of is 3. The problem should now look like this:

Remember to reduce. 15 and 18 are both divisible by 3.

Your answer is .

Add the numerators:

Rewrite these numbers as improper fractions.

Now evaluate:

, so

The least common multiple of 2 and 9 is 18.

Rewrite using the lowest comon denominator. Since :

Rewrite using the lowest comon denominator. Since :

Rewrite both numbers as decimals:

, so

, so

Add the decimals vertically, lining up the decimal points:

Add the numerators: