Rounding to the hundred thousand helps you estimate answers involving large numbers with at least six digits. The number in the ten-thousands place dictates whether you round up or down.
Identify Digits, Then Round
Identify the hundred-thousands place by counting over six digits, starting at the right and moving toward the left. If your number has a decimal, you will start counting with the first number to the left of the decimal. Circle the sixth number. Move over to the number in the ten-thousands place, which is the number to the immediate right of the hundred-thousands place. If this number is 4 or below, the number in the hundred-thousands place stays the same and all numbers to the right of the hundred-thousands place become zeros. For example, the number 223,572 would round to 200,000. If the ten-thousands place has a number 5 or higher, the number in the hundred-thousands place goes up one and all numbers to the right become zero. For example, the number 375,201 would become 400,000. If the digit in the hundred-thousands place is 9 and you need to round up, you also need to increase the number in the millions place by one. For example, the number 3,982,027 becomes 4,000,000.