You've received GREAT responses above.

Being young and/or having small stature are factors not typically given the greatest weight when making a decision about acceleration. Here is a link to prior far-ranging discussions on acceleration, including PROs and CONs on
- Iowa Acceleration Scale (IAS-3, published by the Acceleration Institute),
- single-subject-acceleration (SSA),
- whole-grade acceleration (grade skipping),
- radical acceleration (multiple grade skips),
- social concerns for pre-teens, teens, and early college.

Originally Posted by bethanyc3
... I want to offer him more enrichment (besides the library, piano and museum free days). What did you do with your young child(ren)? What fun (free) activities did they love to pursue?
I'm most familiar with gifted kiddos who needed to have a variety of new things to think about, in addition to their ever-changing special interests. To provide fresh new ideas to process, we had conversations about everyday life; each person, place, or thing we encountered was a potential conversation piece.

For example, play money or coins in our pocket could launch many conversations and led to
- collecting commemorative State quarters, a few foreign coins and historic coins, bible coins and replicas,
- exploring treasure of sunken skips (online, books, museums),
- budgeting,
- understanding basic economics, US Treasury, the concept of bank savings accounts, checking accounts, credit, the stock market, and real estate,
- emerging thoughts of future career and earning one's own money,
- appreciation of the US Constitution and private property rights,
- developing perspective on history and strength of nations,
- budding interest in international trade.

Trips to the grocery store, especially the fresh produce department, were a delight to the senses. A new restaurant opening, or the smell of a new food cooking could launch a cultural study including geography, history, food, clothing, holidays, religious beliefs. Baking or cooking in the kitchen included measuring and exercising the visualization of math skills.

Picking up toys in the play area included sorting, matching, and organizing as each item was put away where we could easily find it again, later.

Don't underestimate kite-flying, laying on your back and observing the changing shapes of clouds overhead, or watching fireflies glow and listening to crickets at night.

Local hardware stores may have a weekly, monthly, or seasonal Saturday morning parent/child class, such as "make a birdhouse."

Restaurants, theaters, or other buildings may offer behind-the-scenes tours by reservation, or annual "Doors Open" days.

Day trips to local cultural events, festivals/fairs, craft shows, pet stores and pet adoption centers, parks, forests, lakes, caves, historic sites, monuments, tourist attractions, shrines/cathedrals/basilicas, visits with extended family, and volunteerism... all provided the entertainment of mini-vacation-escapes with the added benefit of personal educational value. This foundation formed the basis for stimulating curiosity and enthusiasm which fueled proactivity in studying, planning, and preparing to have the best observations and experiences on larger travel opportunities.

Basically we aimed for a well-rounded sampling of experiences with exposure, understanding, and appreciation for our everyday life and all the local/regional area had to offer.