Before Math Rev,my first exam I took without taking Math Rev, I scored Q41. My math skills were very rusty and was not upto GMAT standard.
When first taking GMAT Math Rev, I was surprised how Mr. Lee of Math Rev had GMAT quant figured out inside out. I studied with the videos after work and in weekends as well and it was well worth it. I could feel my math improving as it took less and less time to solve each problems. His Variable approach for DS is really something revolutionary in terms of solving problems quickly and easily which helps for time saving. I highly recommend all students who are preparing for GMAT to take the course. I recommend them to trust their videos and follow their words. To be honest, I feel I still have a lot of room for improvement in my math skills but at least for GMAT quant, Math Rev can help you to meet up with its standard.