Compare Decimals: Find the Missing Sign Between 10.04 and 10.40

To solve this problem, we'll proceed as follows:

• Step 1: Start by comparing the whole number part, which is the integer part before the decimal point. Both $10.04$ and $10.40$ have the integer part $10$.
• Step 2: Since the integer parts are equal, move on to compare the digits immediately following the decimal point, which are in the tenths place.
• Step 3: Observe that in the tenths place, $10.04$ has a $0$ while $10.40$ has a $4$.
• Step 4: Since $0 < 4$, we conclude that $10.04 < 10.40$.

Therefore, we fill in the missing sign as $<$.

Comparing all the choices, choice (1), which is "<", correctly represents the relationship between the two numbers.