The nearest tenth of a number is the first decimal. As can be seen, 8.54 has two decimals, so we must round the first one. If the second decimal was 5 or bigger than 5, then the first decimal would be increased by 1, and 8.54 would be rounded to 8.6. However, the second decimal is smaller than 4, so the first decimal remains the same, and 8.54 is rounded to 8.5.
