Big numbers, groups and arrays

Standard form is the usual way to write a number with digits, such as 73,846. We say it: seventy-three thousand, eight hundred forty-six. Expanded form shows the value of each digit: 73,846 = 70,000 + 3,000 + 800 + 40 + 6. To put numbers in order, count the digits first. A number with more digits is greater, so any 6-digit number is greater than any 5-digit number. If two numbers have the same number of digits, compare them from the left, place by place, until the digits are different. A place value mat helps to line up the places.