Gifted Issues Discussion homepage Forums Age or Ability Specific Forums Challenging word problems/Singapore Maths

thanks for the tip too, can someone help me with purchasing the correct level challenging word problem book. DD is grade 3 but working on grade 5 math. does that mean I should purchase the book 5 in the series? does anyone have the book 3, 4, or 5 and able to give me an example or two of the difficulty level
thanks