Place Value

• The number system that we use in math is called 'base 10', because is uses ten different symbols for counting
• Digits


  • zero
  • one
  • two
  • three
  • four
  • five
  • six
  • seven
  • eight
  • nine
• Number place


  A small box that's only big enough to hold one digit at a time
• If we pick just one more apple, we'll have ten, so we can combine those ten apples into a single group
• Ones place


  Used to count things one at a time
• Tens place


  Used to count groups of ten
• Using the ones place and tens place together, we can represent amounts that are in-between the groups of ten
• We can count all the way from zero up to ninety-nine using only our ten digits and the ones and tens places
• Hundreds place


  Used to count groups of one-hundred
• Each new number place represents groups that are exactly ten times bigger than the previous number place
• Thousands place


  Used to count groups of one-thousand
• Larger number places


  • Ten-thousands
  • Hundred-thousands
  • Millions
  • Ten-millions
  • Hundred-millions
  • Billions
• Many countries use a separator every three places to make the number places easier to keep track of
• Place value


  In a multi-digit number, the number PLACE that a digit is in, determines it's VALUE
• Zeros are used to make it clear what number place a digit is in when the number places are invisible
• Expanded form


  Writing a number as a combination of different groups
• Expanded form


  • 324 = 300 + 20 + 4
  • 6,715 = 6,000 + 700 + 10 + 5