Number Decomposition: Breaking Down 54 into Tens and Units

To solve this problem, let's understand the concept of place value in the given number:

• Step 1: Identify the tens digit. The number 54 has 5 in the tens place. This means it has 5 tens.
• Step 2: Identify the units digit. The number 54 has 4 in the units place. This represents 4 units.

By decomposing 54, we realize that it consists of 5 tens and 4 units. To validate this:

• The tens digit (5) indicates $5 \times 10 = 50$.
• The units digit (4) remains as it is, i.e., 4.
• Combining these values gives us the original number: $50 + 4 = 54$.

Considering the provided multiple-choice answers, Choice 3: "5 tens and 4 units" is correct as it accurately represents the decomposition of 54 using place value.

Therefore, the solution to the problem is 5 tens and 4 units.