Glossary
Equivalent forms
Recognising that 1/2, 0.5 and 50% are the same answer, when the key allows.
Marking that accepts mathematically equivalent answers as correct: a fraction in a different but equal form, a decimal, a percentage, a rearranged expression. The centre's key can also require a specific form, such as simplest fraction, in which case only that form scores.
Next step
See it with your own worksheets.
Twenty minutes on a screen share. Send a worksheet beforehand and you'll be looking at your own material, not a demo.