Little children can be saved without saving ordinances. This is because saving ordinances were designed for those who were under condemnation of a broken law. If no law was broken, there is not condemnation, and where there is no condemnation the mercies of the Holy One of Israel have claim upon them, because of the atonement (2 Nephi 9:25).
If little children don’t need baptism, then one must conclude that they do not need the other saving ordinances of the gospel. Such is the case, for when temple work is done for children known to have died before the age of 8, they are not baptized, not endowed, nor are they ordained to the priesthood. The only ordinance done on their behalf is to be sealed to their parents, for all children who die before they arrive at the years of accountability are saved in the celestial kingdom of heaven (DC 137:10). Joseph Fielding Smith has taught, “Children who die in infancy do not have to be endowed. So far as the ordinance of [marriage] sealing is concerned, this may wait until the millennium.” (Doctrines of Salvation, 2:55)
If little children don’t need repentance or baptism, then they do not need to partake of the sacrament. The entire focus of the sacrament is to renew baptismal covenants, recommit to the Lord, and receive his redemptive power anew. The sacrament is an ordinance for those who have sinned and are in need of repentance. It is not for the innocent. The reason little children partake of the sacrament is not because they need the sacrament for their salvation, as we do—it is to teach them the significance of the ordinance and to remind them of their Savior. Ironically, although they do not need the sacrament like the rest of the congregation, they are the most worthy to partake of it.