Which digit do you focus on when rounding a number to the nearest tens place?

When rounding a number to the nearest tens place, the key digit to focus on is the ones digit. The rounding process involves looking at the ones place to determine whether to round the tens digit up or keep it the same. If the ones digit is 5 or greater, you increase the tens digit by one; if it is less than 5, you leave the tens digit as it is and replace the ones digit with a zero.

For example, if you're rounding the number 47, the tens digit is 4 and the ones digit is 7. Because the ones digit (7) is greater than 5, you would round up to 50. Conversely, if you were rounding 42, the ones digit is 2, which means you would round down to 40. This process highlights the importance of the ones digit in determining how to round to the nearest tens place.