6.5 months old baby will begin to sit alone, with the ability to sit alone, baby can move their hands and arms freely, will pick up the toys in front of them. This period of the baby’s body development began to level off, if the middle and bottom two incisors have not yet grown, this month may grow out; if they have grown out, the top middle two incisors may soon grow out. A full 6-month-old baby boy weighs 5.9-9.8kg and a baby girl weighs 5.5-9.0kg; a baby boy is 62.4-73.2cm long and a baby girl is 60.6-71.2cm long; a baby boy’s head circumference is 44.9cm on average and a baby girl’s head circumference is about 43.9cm on average. At this time, he is able to sit alone and if you put him in a sitting position, he can still remain sitting even if he does not need to be supported by his hands. The development of your baby from a recumbent to a sitting position is a major advance in motor development. As he looks at the world from this new beginning, he will discover that he can do many amazing things with his hands and has the desire and movement to crawl.