Determine how many grams should correspond to the absolute weight of the measured material, if this value is not given in initial conditions. Depending on the specific situation, it can be done in different ways- to weigh, to read the packaging or in the recipe, see the Handbook, technical description, calculate according to the formula etc. In any case, the result of this step you should have two numbers, one of which describes the total weight in grams, and the other fraction of the full weight, not yet measured in percent.
Make the equation in the left part of which shall be the ratio of the total weight (M) in grams to one hundred percent, and the right - the ratio (m) of the whole (in grams) to the unknown quantity of interest (x): M/100 = m/H. we Express with the help of this identity the unknown variable: x=m*100/M. that is, in order to determine what percentage of the total weight in grams is known to you the number of grams, you need to increase this number by two orders of magnitude, and then divided by the total weight.
Take, for example, the built-in Google search engine Nigma, and calculators to calculate the specific values obtained in the previous step formula. If you make calculations in mind, it is not possible, but there is Internet access, then this method of calculation is most simple. For example, if you need to determine what percentage is estimated at 127 grams from the total weight in grams 983, replace the variables in the formula the corresponding values, and type in the search query box 127*100/983. The search engine will calculate and show the result: (127 * 100) / 983 = 12,9196338. This means that 127 g approximately 12.9% of the weight in 983