1. **State the problem:** Given two numbers 15.56 and 3.26, find two numbers that will complete 15.56. 2. **Interpretation:** To "complete" 15.56 using 3.26 and two unknown numbers likely means finding two numbers that add up with 3.26 to equal 15.56. 3. **Set up the equation:** Let the two numbers be $x$ and $y$. Then: $$x + y + 3.26 = 15.56$$ 4. **Simplify the equation:** $$x + y = 15.56 - 3.26 = 12.3$$ 5. **Conclusion:** There are infinite pairs of $x$ and $y$ such that $x + y = 12.3$. For example, $(x,y) = (0,12.3), (6.15,6.15), (12.3,0)$, etc. Without additional constraints, the two numbers can be any pair summing to 12.3.