There are several different types of double facts. Many of the commonest kinds consist of multiplication facts, addition facts, and subtraction facts. In addition, Additionally, there are double facts that involve fractional numbers and decimal figures. Subtraction fluency within 20 is the main target of this guided lesson for 2nd https://www.generationgenius.com/videolessons/strategies-to-add-subtract-within-20-make-a-10-doubles-facts/