Complete the Decimal Sequence: 0.2, 0.3, 0.4, and Three Missing Terms

To solve this problem, let's identify the pattern in the sequence:

Given sequence: $0.2, 0.3, 0.4$.

Step 1: Determine the pattern:

• The first number is $0.2$, the second number is $0.3$, and the third number is $0.4$.
• Calculate the difference between consecutive terms: $0.3 - 0.2 = 0.1$ and $0.4 - 0.3 = 0.1$.
• Therefore, the sequence increases by $0.1$ each time.

Step 2: Use this difference to find the missing terms:

• The next term after $0.4$ will be $0.4 + 0.1 = 0.5$.
• The next term after $0.5$ will be $0.5 + 0.1 = 0.6$.
• The next term after $0.6$ will be $0.6 + 0.1 = 0.7$.

Thus, the completed sequence is $0.2, 0.3, 0.4, 0.5, 0.6, 0.7$.

Comparing the given choices, the correct sequence is choice 3: $0.5, 0.6, 0.7$.

Therefore, the missing terms are $0.5, 0.6, 0.7$.