100 out of 650 million of people having a physical disability in the world need wheelchairs.

Summary: Wheelchair-Accessibility Issues

100 out of 650 million of people having physical disability in the world need wheelchairs. The existence of a wheelchair makes people with disability embrace independent lifestyle. On the other hand, the adversity of this moving tool: strenuous, large, and hard to maneuver on slippery surfaces and steep slopes. One of the most difficult places for wheelchair users is house. There are many parts of house which require certain condition such in bathroom with grab bars, higher toilet seats, and built-in shower seats. Many nations have rules demanding public buildings to be wheelchair friendly. The exterior needs: wide sidewalks and automatic doors, whilst the interior necessitates wide corridor and the restroom must be accessible. In advancement of technology era, the disabled could drive a car with a portable ramp. Many cities have already had subway and bus system to serve wheelchair user to the utmost. In most developing countries, an enormous attention does not come from wheelchair accessibility as access to wheelchair.

Hi Wasisha..
These are my a few corrections for your summary.

... of people having A physical disability in ...
... with disability embrace AN independent lifestyle.
... for wheelchair users is A house. There are many parts of THE house which require , REQUIRING (you should conduct reducing here) certain condition such in A bathroom with grab bars, ...

... demanding public buildings to be THE TRACK OF wheelchair friendly.
... interior necessitates wide corridor and ...
Many A LARGE NUMBER OF cities have already had A subway and bus system to serve THE wheelchair user ...
... as access to THE wheelchair.
Note: Actually, your summary is a good job. However, you still make mistakes grammatically, especially use of articles. Besides that, you should make your sentences more various. you can use the technic of both reducing and omitting. Turning to the flow, you can display your information well. You only need harnessing the linking words to make your move smoother. I really believe you can show the better progress if you wanna practice more and more

Overall, GOOD JOB
Keep Writing
GOOD LUCK