A 30g bowl of Sainsbury's Frosted Malties contains 111 kcal, 6.1g of sugar (all of it free sugar), 2.8g of fibre and 2.8g of protein. With 125ml of semi-skimmed milk the bowl comes to 169 kcal and 12.0g of total sugar. It is classed as NOVA 4 (ultra-processed).
All 20.4g of sugar per 100g in Frosted Malties counts as free sugar, because it comes from added sugars rather than whole fruit or milk. A 30g bowl gives 6.1g, about 1.5 teaspoons.
Frosted Malties is classed as NOVA 4, ultra-processed, because its ingredients include invert sugar. These are industrial ingredients you would not use in a home kitchen. 1 of its 6 ingredients is of this kind.
Boone classifies processing from the published ingredient list using the NOVA system. Added vitamins and minerals are not counted as a marker of ultra-processing.