When calculating the sum of two numbers with different signs, we subtract the lesser absolute value from the greater absolute value.
8.5
Practice makes perfect
We want to find the sum. Let's look at the given expression!
- 4.3+ 45+ 12Before we can evaluate our sum, let's rewrite all numbers as decimals.
- 4.3+ 45+ 12
⇕
- 4.3+ 0.8+ 12
Now we can use the Commutative Property of Addition to simplify the expression.
- 4.3+ 45+ 12
⇕
0.8+ 12+( - 4.3)
Next, we can find the sum of two numbers with the same sign. We can do so by adding their absolute values.
| 0.8|+| 12|&= 0.8+12
&= 12.8
Now, we can simplify our addition.
0.8+ 12+( - 4.3)= 12.8+( - 4.3)
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.
| 12.8|=12.8and| - 4.3|=4.3
Notice that | 12.8| is greater than | - 4.3|. This means that we should subtract | - 4.3| from | 12.8|. Let's do it!
