Complete 21__ to Make it Divisible by 4

To solve the problem, we will ensure the two-digit number formed from the missing blanks at the end of 21 is divisible by 4. This requires performing the following steps:

• Step 1: Identify combinations for the blanks. Since this is a two-digit number, consider each combination within the range of numbers provided.
• Step 2: Check divisibility. Once the numbers are identified, check if they are divisible by 4.
• Step 3: Validate the correct number. The rule is that it must divide evenly with no remainder.

Numbers formed by potential combinations from the given choices are:
- $212$, $214$

Now, let's check each of these numbers:

• $212$: Dividing 212 by 4 gives $212 \div 4 = 53$. This is an integer, meaning 212 is divisible by 4.
• $214$: Dividing 214 by 4 gives $214 \div 4 = 53.5$. This is not an integer, hence 214 is not divisible by 4.

After evaluation, the number $212$ is divisible by 4.

The numbers that fill the blanks and ensure divisibility by 4 are 2, 4.