We want to check whether our friend is correct. Let's start by calculating the sum of - 3.7 and - 0.25. Notice that - 3.7 and - 0.25 are negative numbers. This means that we want to find a sum of two numbers with a common sign. Let's recall the rule for the addition of rational numbers with the same sign!
Add the absolute values of the rational numbers. Then use the common, positive, sign.
2.2+5.1=7.3
Addition of Negative Rational Numbers
Add the absolute values of the rational numbers. Then use the common, negative, sign.
- 2.1+(- 5.2)=- 7.3
Looking at the table, we can see that we will use the rule for adding negative rational numbers. We can start by calculating the absolute values of - 3.7 and - 0.25.
| - 3.7|=3.7 and | - 0.25|=0.25
Now we calculate the sum of | - 3.7| and | - 0.25|.
| - 3.7|+| - 0.25|&=3.7+0.25
&=3.95
The sum of | - 3.7| and | - 0.25| is 3.95. Recall that the sum of two negative numbers is also negative. This means that the sum of - 3.7 and - 0.25 is equal to - 3.95. This result does not correspond to our friend's answer.
