What is 5.30 plus 1.76 plus 4.079 by rounding?

Answer 1

Adding by rounding is making the terms simpler. Turn 5.3 to 5, remember that 0.3 was subtracted. Turn 1.76 to 2, remember 0.14 was added. Turn 4.079 to 4, remember 0.079 was subtracted.

5+2+4=11

Now the three numbers:

0.3+0.079-0.14=0.239

11+0.239=11.239