I couldn't get the picture to post but if you bring up this link
Cheerios, it'll show the nutritional value from the box.
The serving size is 1 cup
Total Carbohydrates: 20 grams
Dietary Fiber: 3g
Soluble Fiber: 1g
Sugars: 1g
Other Carbohydrates: 16g
Looking at some of the ingredients, "other carbohydrates" would be the modified corn starch & the corn starch.
If you add up the fiber (3g) & the sugar (1g) & other carbohydrates (16g) you get a total of 20g.
They are not counting the 1g of soluble fiber in the total count because it has a different affect on blood sugars.
Functions of Soluble Fiber
bind with fatty acids
prolong stomach emptying time so that sugar is released and absorbed more slowly
Benefits of Soluble Fiber
lower total cholesterol and LDL cholesterol (the Bad cholesterol) therefore reducing the risk of heart disease
regulate blood sugar for people with diabetes
Food Sources of Soluble Fiber
Oat/Oat bran
Dried beans and peas
Nuts
Barley
Flax seed
Fruits such as oranges and apples
Vegetables such as carrots
Psyllium husk