This set of subtraction and composing and decomposing online activities focuses on the following foundational skills:

• Composing/Decomposing Numbers with Tens and Ones
• Subtracting With Objects, Pictures and Equations (Subtraction)

Games linked from this page practice Common Core Standards:

• K.OA.1 – Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
• K.OA.2 – Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.
• K.OA.5 – Fluently add and subtract within 5.
• K.NBT.1 – Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (such as 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.