asÂ·soÂ·ciÂ·aÂ·tive property. The property of addition and multiplication which states that a difference in the grouping of numbers being added or multiplied will not change the result, as long as the order of the numbers stays the same. For example, 3 + (4 + 5) is equal to (3 + 4) + 5. See also commutative property, distributive property. 1  Facebook.
The most common recommendation is to initially place infants to sleep on their backs for the first 12 months. However, when the infant is able to roll over on their own in to the sleep position of his/her choice than it is fine to leave the baby in that position. My children are now 29, 27, 24, and 11.
The experts unanimously agree on the average child's need to nap and on a napping schedule: Newborns sleep as much and as long as they need to. Between 4 and 12 months, babies move to two naps a day, one in the morning and one in the afternoon, each ranging from 20 minutes to three hours.In their second year, most toddlers go down for one two-hour nap in the middle of the day, and by their third birthdays, some will have given up naps entirely.ears' view. Most toddlers this age still need at least one hour-long nap in the afternoon, which may actually help your child fall asleep more quickly and efficiently at night. Even if yours doesn't, a little quiet time â for her and you â won't hurt.