Strange float behaviour on Arduino Mega

Is it the same as printing "7 significant digits" that inludes digits before and after the decimal point? For example:

float y1 = 1.23456789;
Serial.println(y1, 6); //shows: 1.234568 (roundng)
//-------------------

float y2 = 1234.56789;
Serial.println(y2, 3); //shows:1234.568 (rounding)

In this float number 1234.568: there are 7 significant digits (1234568), 3 precise digits (568), and 2 accurate digits (56). Am I correct?