Several vertebrate species can distinguish between, say, two and five bananas—but with the exception of primates, they can’t grasp the numerical rules that would let them arrange their piles of fruit ...

Children who count on their fingers between ages 4 and 6.5 have better addition skills by age 7 than those who don't use their fingers, suggesting that finger counting is an important stepping stone ...

Several vertebrate species can distinguish between, say, two and five bananas—but with the exception of primates, they can’t grasp the numerical rules that would let them arrange their piles of fruit ...