Evaluate $2.5+\left(-8.1\right)$2.5+(−8.1).
Evaluate $-8.3+8.9$−8.3+8.9.
Evaluate $5.4+\left(-7.8\right)$5.4+(−7.8).
Evaluate $-7.2+3.3$−7.2+3.3.
Apply and extend previous understandings of numbers to add and subtract rational numbers.
Add and subtract rational numbers.
Apply and extend previous understandings of numbers to multiply and divide rational numbers.
Multiply and divide rational numbers.