Well, I thought you might look to more recent educational resources that narrow the big bang to 13.799±0.021 billion years. The "about" is in that +/- .021 or 21 million years old. Pretty precise, huh? But your 13.8 billion years will work, as long as your meaning of "about" is within a reasonable amount of time, let's say less than a billion years of inaccuracy.
When I was in college 35 years ago, "education" stated that the age of the universe was about 9 billion years old using the Harwit model and a Hubble constant of 75. After the Hubble telescope provided some deep field images, certain quasars in those images appeared to be older than the universe itself. Soon afterward, the age of the universe and the big bang theory had changed almost miraculously by new scientific data. That was when I started to doubt scientific theories ofthe universe. Even today, there are some models that suggest that there was no big bang,and that the universe has always existed.
I bring this to your attention, because your reliability in "education" and wikipedia, leads me to believe that you therefore have determined that the universe is 13.8 billion years old. Something even more educational will be occuring soon. A new space telescope, the JWST is scheduled to be launched in October of 2018. The Hubble telescope was restricted by how far in the past it could view images. This is because of the red shift in the light sources moving away from the earth. The JWST will be using infrared image viewing so that light sources in the infrared range will become viewable. Why is this important? Should the data from the infrared images similarly show that star systems exist in which stars were created more than 13.8 billion years ago, then "education" will be proven false. However, no scientists will consider the big bang theory false. No, it will be changed to conform to an adjusted theory that continues to disprove the existance of God. I hope at that time, you will consider looking into the possibility that the Bible has been true all along. I did. All you have to do is promise to yourself that if that JWST proves wikipedia wrong, I will come back to this forum and start asking for evidence that the Bible is true.
See ya in 2018!