private function calculate_grade_from_children( $children, $student ) {

		$grade  = null;
		$grades = array();

		// Loop through all the children and compile the overall grade & points data.
		foreach ( $children as $child_id ) {

			$child = llms_get_post( $child_id );
			$grade = $this->get_grade( $child_id, $student, false );

			// Non numeric grade (null) hasn't been taken yet or no gradable elements exist on the child.
			if ( ! is_numeric( $grade ) ) {
				continue;
			}

			$points = $child->get( 'points' );

			// If no points assigned to the child, the grade doesn't count towards the overall grade.
			if ( ! $points ) {
				continue;
			}

			// Add the grade & points for further processing after we have all the data.
			$grades[] = array(
				'grade'  => $grade,
				'points' => $points,
			);

		}

		// If we have at least one grade.
		if ( count( $grades ) ) {

			// Get the total available points for all children with a numeric grade & a points value.
			$total_points = array_sum( wp_list_pluck( $grades, 'points' ) );

			// If we don't have any points this element can't have an overall grade.
			if ( $total_points ) {

				// Sum up the adjusted grade.
				$grade = 0;
				foreach ( $grades as $data ) {
					// Calculate the adjusted the grade.
					// Grade multiplied by available points over total points.
					$grade += $data['grade'] * ( $data['points'] / $total_points );
				}
			}
		}

		return $grade;

	}