1. The problem is to find the sum of the numbers 137.573, 2.578, and 56.89. 2. Add the numbers step-by-step: $$137.573 + 2.578 = 140.151$$ 3. Now add the result to the last number: $$140.151 + 56.89 = 197.041$$ 4. Therefore, the sum of 137.573, 2.578, and 56.89 is **197.041**.