Answer:look at the downStep-by-step explanation:1. What is asked in? answer:How far did Alvin walk in total?2. What are the given facts? answer:Alvin walked 0.30 km to Dino's house and 0.50 km to the zoo.3. What is the operation to be used? ans:Addition4. What is the number sentence?ans: 0.30 km + 0.50 km = N5. What is the solution?answer: 0.30 km + 0.50 km = 0.80 kmAnswer: Alvin walked a total of 0.80 km.