Respuesta :

To estimate, you can round each decimal to the nearest whole number, and then add them up together to get a number close to the real answer.

I hope this helps! :)
4.64 + 2.44= 7.08 so about 7
6.666 + 0.34= 7.00600 so about 8 or 7
12.86 - 7.0064= 5.8536 so about 6