Step Three - Eligibility is decided. Together the parents and group of professional review the results and together they decide if the child is a “child with a disability,” as defined by IDEA.
Step Four - This step is that the child is found eligible for services.
Step Five - The IEP meeting is scheduled with school staff in the special education department.
Step Six - Then the IEP meeting is held, and the IEP is written.
Step Seven - This when the IEP is written, and the services are provided.
Steps Eight, Nine, Ten - Is done yearly to report the progress to the parents, add in new goals, tests that need to be done. Child is reevaluated every 3 years.  

Down Syndrome students in the past use to go to separate schools for students with intellectual disabilities. But most now make better progress in schools along with their peers. Students with Down Syndrome will do better when inclusion is embraced and supported as part of the school culture. Where different learning needs of all students are acknowledged and properly addressed. 

Education rights through DRNC enforces that student with disabilities can go to public school from 3 years old through 22 years old. 

Inclusion - They should be full members of age-appropriate inclusive classes, to have more opportunities for peer relationships to occur.
Building self-esteem - Build confidence and instill pride
Progressive learning - always strive for them to move progressively along the learning continuum.
Minimize distractions - keeping a structured environment, away from windows, noise level down, and know the expectations of the rules and routines.
Employ speech-and-language instruction -Teachers should use patience and model appropriate interactions at all times.
Behavior-management techniques -Strategies used for other students should not differ for the student with Down syndrome. Positive reinforcement is a much better strategy than punitive techniques. Reinforcers need to be meaningful.

Reference: Behavior and Classroom Management in Special Education (thoughtco.com)

Talk about your day-to-day activities

Use visual cues

Copy their response - like if they smile you smile back at them

Be animated in interacting - copy their expressions, helps them to get hooked and pay attention to you

Use repetition - it's helpful to repeat words and ideas to them  

Show your pleased with them - smile be cheerful when talking to them

Stay physically close to them, it's comforting to them. 

Be patient with them!

Reference: Tips: Communicating with a Person with Down’s Syndrome (belovedshepherd.com)