An electronic scale functions in a normal and a high sensitivity measurement regions. The weights of mother alone and mother plus infant are measured in the high sensitivity region. The difference between the two measurements is the weight of infant alone, which is displayed with a finer scale interval than the normal one. The high sensitivity region is automatically shifted for covering the two measurements. The degree of shift is stored to correct the absolute mother weight. The infant weight is transmitted to a mobile phone, which displays growth curve of infant in comparison with a statistics growth curves provided by a server through the internet. The infant weight is uploaded to the server for incorporation into the statistics. The statistics is based on data gathered form a plurality of mobile phones, which are each authenticated to increase reliability of the statistics against false weight data upload.
