When calculating the sum of two numbers with different signs, we subtract the lesser absolute value from the greater absolute value.
133 or 4 13
Practice makes perfect
We want to find the sum. Let's look at the given expression!
5 13+ 7.5+( - 3 16)
Before we can evaluate our sum involving mixed numbers, let's rewrite all numbers as fractions.
Number
a bc
a* c+b/c
Simplified Fraction
5 13
5 13
(5* 3+1/3)
16/3
7.5
7 12
(7* 2+1/2)
15/2
- 3 16
- 3 16
- (3* 6+1/6)
- 19/6
When adding or subtracting fractions they should have the same denominator. In this case, we have three fractions with different denominators.
5 13+ 7.5+( - 3 16) [0.3em] ⇓ [0.3em]
16/3+ 15/2+( - 19/6)
Since 6 is a multiple of both 2 and 3, we can start by multiplying both the numerator and denominator of 163 by 2 to create a common denominator.
Now, we can find the sum of two numbers with the same sign. We can do so by adding their absolute values.
| 32/6|+| 45/6|&= 32/6+45/6
&=77/6
Now, we can simplify our addition.
32/6+ 45/6+( - 19/6)= 45/6+( - 19/6)
Next we can add two numbers with different signs. We can do so by subtracting the lesser absolute value from the greater absolute value. Then, we will use the sign of the number with the greater absolute value. First, we will calculate the absolute value of the numbers.
| 45/6|=45/6and| - 19/6|=19/6
Notice that | 456| is greater than | - 196|. This means that we should subtract | - 196| from | 456|. Let's do it!
