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.
1 Always put your baby down to sleep on his or her back. 2  Always use a firm sleep surface. 3  Car seats and other sitting devices are not recommended for routine sleep. 4  Your baby should sleep in the same room as you, but not in the same bed as you.5  Keep soft objects or loose bedding out of the crib. Always put your baby down to sleep on his or her back. 2  Always use a firm sleep surface. 3  Car seats and other sitting devices are not recommended for routine sleep. 4  Your baby should sleep in the same room as you, but not in the same bed as you.