The L3 Innovation Challenge is a design challenge bootcamp hosted by Youth Cities to immerse middle- and high-school students in innovation, design thinking, entrepreneurial problem-solving, and prototyping. It’s like a 24-hour hackathon, but it’s spread out over seven weeks, during which students play the role of Boston Children’s Hospital’s Innovation Team to address a specified challenge. It has mandatory meetings every Wednesday from 5PM to 8PM from October 2 – November 13 at LabCentral in Cambridge. Pizza is provided. The cost is $570, and need-based scholarships are available. Apply by September 25.

Separately, you can also sign up for notice of Youth Cities’ monthly mini-hacks, which are two-hour white-board brainstorming sessions facilitated by local entrepreneurs and open to middle- or high-school teens, college students, entrepreneurs, educators, public officials, and other working professionals. They’re held at the Cambridge Innovation Center on the second Thursday of each month (except July-August) at 4:30-6:30PM,  the same time that the CIC hosts Venture Cafe.

Admission fees (except planetarium and Explorer Express Train) at Worcester’s EcoTarium are half-price in September.

The Science Club for Girls is an after-school program that “fosters excitement, confidence and literacy in STEM for girls from underrepresented communities by providing free, experiential programs and by maximizing meaningful interactions with women mentors.” SCFG is currently recruiting mentor scientists to lead clubs and serve as role mondels. You can apply here for these locations, days, and grade levels:

• Cambridge: Tuesdays (Grades K-5), Fridays (Grades K-5 and 4-5)
• Dorchester: Fridays (Grades 4-5)
• Somerville: Tuesdays (Grades 3-5), Wednesdays (Grades K-5)

The Noyce Legacy Fund will match your donations to the Science Club for Girls — up to a total of $100,000 — to expand SCFG’s free, fun, and authentic programming in Cambridge, Boston, and Somerville.  SCFG says:  “SCFG fosters excitement, confidence and literacy in STEM for girls from underrepresented communities by providing free, experiential programs and by maximizing meaningful interactions with women mentors. Young women, especially low-income, first generation college-bound, and students of color, are persistently underrepresented in STEM. They need on-ramps, mentors, and enrichment programs to show that STEM needs them and is meaningful to their lives. SCFG addresses a critical need, offering a continuum of engaging activities in STEM for K-8 girls, leadership experiences for high school girls, and adult mentoring by committed women in STEM to create a broad pipeline of future STEM talent.” Donate here to have your donation matched.

MassBay Community College in Wellesley runs a STEM Mentor Program in which STEM professionals meet with its students at least once a month during the school year. Activities during the year include periodic STEM Forums, a Robo-Sports competition, hands-on STEM activities, and tours of four-year colleges and local STEM companies. Learn more in this STEM Mentor Program brochure. For more information, contact Valerie Kapilow, STEM Starter Academy Project Director, at vkapilow@massbay.edu or 781-239-3157.

The Microsoft store in the Natick Mall hosts a series of free summer camps, available in various schedules (two-hour, two hours daily over four days, etc.) and for various age groups (ages 6+, 8+, 13+, young professionals, etc.).