Shaping is a change obtained in the external shape of a raw material when the raw material is processed. Raw material is a material or a part that is not yet processed. There are many shaping techniques. To categorize them, a simple algebra of addition and subtraction can help. There are the following three shaping categories based on a change in the amount of a raw material: (1) Subtraction: the product weighs less than the raw material; the technique is subtractive, (2) no change: the product weighs similar to the raw material; the technique is formative, and (3) addition: the product weighs more than the raw material; the technique is additive. Subtractive techniques are machining, drilling, honing, etc. For some shaping techniques, their category is not straightforward, whether they are formative or additive, for which an explanation is given.