The question of how the number zero is represented in the brain has only recently been studied in the field of neuroscience. Last year, researchers examined the ability of human brains to represent the concept of zero. In the study, they found neurons in the brain specifically responded to the concept of zero both in symbolic (the digit 0) and nonsymbolic (the empty set) forms, suggesting that the brain interprets zero as part of the number system. When zero was presented to participants symbolically, neurons processed zero just like other numbers. On the other hand, when zero was presented as an empty set, the neurons had a slower response, suggesting that the brain requires more time to process abstract representations of zero. 

This new study offers math educators with valuable insight into how the human brain interprets abstract representations of zero and why children take longer to grasp the concept of zero compared to other numbers. 

“It took a long stretch of human history for zero to be recognized and appreciated. Children show a delayed understanding of the concept of zero numerosity, long after they comprehend positive integers,” researchers Florian Mormann and Andreas Nieder, explain to PsyPost about their study. “For a brain that has evolved to process sensory stimuli (‘something’), conceiving of empty sets (‘nothing’) as a meaningful category demands high-level abstraction. It requires the ability to represent a concept independently of experience and beyond what is perceived. The brain needs to interpret ‘nothing’ as ‘something,’ as a mathematical object.”  

Zero in the Classroom

“Awareness of the meaning behind the number zero develops in phases,” says Colleen Uscianowski Maas, a researcher with Development and Research in Early Mathematics Education (DREME) based at Stanford University. “Around age 4 is when children begin to understand the meaning of an empty set as the lack of something that would typically be there. Children initially learn to recognize the zero symbol (0) without knowing what it means.” 

The team of researchers at DREME explores how children learn the concept of zero and develop an understanding of the empty set. Even after formally learning the meaning of zero (“none, nothing, nil, zilch”), children struggle to understand its function as a number with a place value and position on the number line.  

Maas suggests that children may struggle with such tasks because the mathematical term zero feels distinct from the concept of nothing or negation. For instance, in one study by DREME, children were asked to not give balls to the bird in two different ways: “give zero balls to the bird” and “do not give any balls to the bird”. The children understood the directions when the word “zero” was not used. 

In this month's blog:

• 5 ideas for helping children understand zero
• A look at the history of understanding zero
• Video and podcast suggestions