Add thirty-eight and nine tenths, five and fifty-eight hundredths, seven, and fifteen

and eight tenths.

A~1662?

That doesn't look right.

38.9 + 5.58 + 7.0 + 15.8

Guestimating -- the answer should be in the 60s.

What answer do you get?

38.9 + 5.58 + 7 + 15.8

Significant digits will round to the whole number due to the 7.

67.28

67.28?

Right. 67.28 is correct.

Yes, 67.28. I would not do any rounding off (to 67) unless told to.

To add these numbers, we can break it down into three steps:

Step 1: Add thirty-eight and nine tenths, and five and fifty-eight hundredths.
To do this, we add the whole numbers separately and add the decimal parts separately.

38 + 5 = 43

0.9 + 0.58 = 1.48

Step 2: Add the result from step 1 with seven.
We can simply add the whole numbers together:

43 + 7 = 50

Step 3: Add the result from step 2 with fifteen and eight tenths.
Once again, we add the whole numbers separately and the decimal parts separately.

50 + 15 = 65

0.8 + 0.08 = 0.88

So, the final answer is 65 and 88 hundredths, or 65.88.