Math Background

Place Value and Money: When Students Ask

  • Why should I learn about place value and money?
    Use this question to initiate a class discussion about situations where not knowing much about place value or money would be a problem. Here are a few suggestions.
    1. You give a clerk a $20 bill for a hat that costs $8.95. The clerk gives you a nickel and a $1 bill in change. (You are missing $10.00.)
    2. The class that collects the most canned goods for the canned food drive gets a trip to the amusement park. Your class collected 1,547 canned goods. The other fourth-grade class collected 1,457. It's up to you to determine the winner. (1,547>1,457)
  • Why do I have to put commas in numbers?
    Explain to students that commas are used to separate periods, or groups of three digits in a number. They can use commas to help them read greater numbers. When they see a comma, they say the name of the period.

    642,700,391 ---> six hundred forty-two million, seven hundred thousand, three hundred ninety-one

  • When I count money, why should I start with the bill or coin of the greatest value?
    Give students an example to illustrate that counting money of decreasing value is easier than counting money of increasing value.
    counting money of decreasing value and counting money of increasing value
  • Why do I have to start at the left to compare numbers? Why can't I start at the right?
    Point out to students that they compare numbers starting with the greatest place value. The greatest place value is the place on the far left.

Houghton Mifflin Math Grade 4