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.
Today, as more babies sleep on their backs, fewer than half that many babiesâabout 2,000âdie from SIDS every year. These statistics support the recommendation that you should always place your baby on his or her back to sleep.esearch shows that the back sleep position is the safest for babies. The back sleep position carries the lowest risk of SIDS. Research also shows that babies who sleep on their backs are less likely to get fevers, stuffy noses, and ear infections.