Does anyone know of any credible personal tutors in Manila? Specifically grade school math?

Personal tutors, in my opinion, aren't the way to go. Though, I guess it depends on your children's strengths and weaknesses. I would first suggest you check out placed like Tutoring Club and Kumon. They're very reputable learning academies and offer a school-like environment where your kids can flourish academically and even socially! If you prefer personal tutors, here's a link to helpful website: http://www.myprivatetutor.ph/location/1/Manila-private-home-tutors.html

Kumon is a leading expert when it comes to English and Mathematics. Some math wiz are even enrolled there so they can hone their knowlegde even more.