600 mL corresponds to 15 teaspoons of sugar
That gives the ratio 600:15
Divide both parts of that ratio by 3 so we get to 200:5
Then multiply both parts by 10 to get 2000:50
This says 2000 mL, aka 2 liters, of soda has an estimated 50 teaspoons of sugar.
To convert from teaspoons to grams, we multiply by 4. This is directly from the equation of 1 teaspoon = 4 grams of sugar
So 50 teaspoons = 50*4 = 200 grams of sugar.
To go from grams to teaspoons, we divide by 4.
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To find the actual amount of sugar, you'll need to find a 2 liter bottle of soft drink and look at the nutrition facts label. You can search for the nutrition facts label online if you don't have a bottle near you. Keep in mind you're looking for the 2 liter plastic bottle version and NOT the 12 fluid-ounce can version.
Also, keep in mind that the nutrition facts label will list the amount of sugar per serving. This isn't the total sugar since it's just a small portion. Multiply the number of servings by the amount of sugar per serving.
Example: If there are 7 servings and 20 grams of sugar per serving, then that's a total of 7*20 = 140 grams of sugar total.
Side note: the amount of sugar will vary from brand to brand. However, they should all be in the same basic ballpark.
