Before beginning reading activities on implicit/explicit facts, third grade students need to know the definition of these two terms.
Students will probably not be familiar with the vocabulary words: implicit or explicit. So, you will need to teach these definitions and then practice the concept with reading activities.
You can explain the terms using an example. Put these two examples on the chalkboard or chart paper. First, write: "There are 8 planets." Next to this write explicit fact. Then write the names of the eight planets on the other side of the board: "Mercury, Venus, Earth, Mars. Jupiter, Saturn, Uranus and Neptune. I know there are 8 planets from this list." Next to this write implicit fact.
With this learning activity on implicit/explicit facts, third grade students can start to understand that implicit facts are stated by gathering information and coming up with a fact. Explicit facts are stated, and there is no question. You can also give students the definition of the two words to help them understand the concept also. Implicit means, "implied or not specifically stated." Explicit means, "leaving nothing implied or clearly stated."
With some students, you may need to review the difference between a fact and an opinion.