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.
My Baby Will Not Sleep On It's Back Date: 17 Sep 1998 My 1month old son refuses to go to sleep on his back or side. He just started this about 2wks ago.When he is put down to sleep on his back or side he just screams.Nothing we do seems to work.y Baby Will Not Sleep On It's Back Date: 17 Sep 1998 My 1month old son refuses to go to sleep on his back or side. He just started this about 2wks ago.