Renaissance, owned by British private equity firm Permira, provides cloud-based education software, including reading and assessment tools that the company says are used by nearly 20 million students and teachers.
Google Capital was formed in 2013 to invest in technology start-ups. Its investments include SurveyMonkey, an online survey company, and Lending Club, a service that matches people seeking loans with people willing to make them.
The Renaissance investment is Google's first in education.
New York Times said on Wednesday Google's investment was $40 million.
Earlier in February, SlickLogin, an Israeli developer of sound-based password alternative, announced it was being acquired by Google. The deal was a "acqui-hiring deal", which means SlickLogin's staff and knowledge will be integrated into Google. SlickLogin confirmed the deal on its website.
"Today we're announcing that the SlickLogin team is joining Google," Xinhua quoted the three founders of the young start-up as saying. They added that Google "shares our core beliefs that logging in should be easy instead of frustrating... We couldn't be more excited to join their efforts."
No financial figures of the transaction were disclosed. SlickLogin was founded less than a year ago. The company is based on a novel idea to enable end users to log-in easily into password-protected websites by using a uniquely generated sound.The company is yet to launch a commercial product and has not accrued clients, so the deal actually represents an acquisition of the technology itself.