Four is very fast to do when you multiply by 2. Here's a little good advice --please just always double twice!BEST OF TIMES gives kids an intuitive understanding of multiplication, encouraging them to arrive at answers on their own rather than memorizing the times tables. A child who can multiply by two, for instance, can multiply by four and even eight! Likewise, times six builds on times two and times three.With his common-sense approach, Greg Tang encourages kids to solve problems creatively, building both their skills and their confidence.