Rachel Riley thrilled her fans on Wednesday when she shared some news that many of them expressed their excitement about.Taking to Instagram, the glamorous star, who is currently pregnant with her second baby, revealed that another launch is also getting closer.SEE: Rachel Riley dresses her bump in stunning white mini dress for London night out - and she looks so radiantSharing a promotional video for her new maths book, At Sixes and Sevens, the maths whiz wrote: "I’m delighted to reveal the