Solving Problems by Subtracting Decimals

Question

The table shows your swim times for the last three triathlons you have entered. How much faster were you in Race 3 than in Race 1?
Triathlon Swim Times
Swimming Time (minutes)
Race 1 14.05
Race 2 13.20
Race 3 12.95
We're asked to find "how much faster," and that is _______ problem, which means subtraction

14.05-12.95=_____

We were 1.10 minutes______ in the 3rd race than in the first.

Check the answer by using estimation: _____- 13 = 1 minutes, which is close to the actual answer of 1.10 minutes.

Answer 1

To find out how much faster you were in Race 3 than in Race 1, we need to subtract the swim time of Race 3 from the swim time of Race 1.

1. Identify the times:

   • Race 1: 14.05 minutes
   • Race 3: 12.95 minutes

2. Set up the subtraction: \[ 14.05 - 12.95 \]

3. Perform the subtraction: \[ 14.05 - 12.95 = 1.10 \]

So, you were 1.10 minutes faster in Race 3 than in Race 1.

4. Check the answer using estimation:
   • For estimation, round Race 1's time to 13 minutes.
   • Then do the estimation: \[ 13 - 12.95 \approx 1 \text{ (this is very close)} \]

Thus, the complete statement would be:

"We're asked to find 'how much faster,' and that is a subtraction problem, which means subtraction.

14.05 - 12.95 = 1.10.

We were 1.10 minutes faster in the 3rd race than in the first.

Check the answer by using estimation: 13 - 12.95 = 1 minutes, which is close to the actual answer of 1.10 minutes."