Final answer:
The number halfway between -38.7 and -38.71 is -38.705.
Step-by-step explanation:
To find the number halfway between -38.7 and -38.71, we can use the average of the two numbers. To do this, we add the two numbers together and then divide by 2:
(-38.7 + (-38.71))/2 = -77.41/2 = -38.705
So, the number halfway between -38.7 and -38.71 is -38.705.