Answer:
30 grams
Step-by-step explanation:
To estimate using mental math, make 340 grams become 360 grams (because 12 fits into 36 perfectly). Now if you divide 360 by 12 you get a whole number: 30. Therefore you can estimate that there are about 30 grams of carbs in a serving.
The answer is reasonable because you changed 340 to a number that can easily work with 12 and is the closest (closer than 240), so you would get a not far-off answer.
