**possible
related topics** collecting like
terms, dimensions, units

Learners might think about adding mass to temperature or
combining other different units in nonsensical ways, or errors such as , where
thirds and fifths can’t be added together in that manner. They might also think
of algebraic errors such as 3*a* + 2*b* = 5*ab*, etc. There are
occasions in science, however, where a value (e.g., the speed of light) is
taken as unity (1), so that mass and energy, for instance, *could* be
added together.

**www.mathematicalbeginnings.com**

© Colin Foster 2012, www.foster77.co.uk