kelly subtracted 2.3 from 20 and got 17.7.explain how this answer is reasonable
20 minus 2 is 18
17.7 is almost 18
20-2 is 18 and 17.7 is almost 18
To understand why Kelly's answer of 17.7 is reasonable when subtracting 2.3 from 20, we can follow these steps:
1. Start with the original number, 20.
2. Determine the amount to subtract, in this case, 2.3.
3. Subtract 2.3 from 20: 20 - 2.3 = 17.7.
Now, let's analyze the reasonableness of the answer:
1. Consider the magnitude: The difference between 20 and 2.3 is significant. Subtracting a smaller number from a larger number would result in a smaller difference, which aligns with the answer being less than the original number.
2. Check the direction of the subtraction: Since Kelly subtracted 2.3, the answer should be less than 20. And indeed, 17.7 is less than 20.
3. Estimate: When estimating the answer, we can round the numbers. Rounding 2.3 to 2 and subtracting it from 20 gives us an estimate of 18, which is reasonably close to 17.7.
Thus, based on these considerations, Kelly's answer of 17.7 seems reasonable when subtracting 2.3 from 20.