Chapter 1 - Whole Numbers - 1.7 Rounding Whole Numbers - 1.7 Exercises - Page 75: 66

Ten-million: 557,460,000,000; Hundred-million: 557,500,000,000; Billion: 557,000,000,000.

To round to the nearest ten-million, we see that the digit to the right of the ten-millions place is 3, so we round down and keep the same value (557,460,000,000). To round to the nearest hundred-million, we see that the digit to the right of the hundred-millions place is 6, so we round up to the next biggest hundred-millions value (557,500,000,000). To round to the nearest billion, we see that the digit to the right of the billions place is 4, so we round down and keep the same value (557,000,000,000).