Math Background

Time Intervals and Money Amounts: When Students Ask

  • Why should I bother learning about time and money?
    Explain to students that time and money are math topics they use almost every day. Ask them what they think the world would be like if there were no method for telling time and no bills and coins to use for money. Their responses will probably be quite interesting!
  • When I count money, why should I start with the greatest value?
    Have students try counting a collection of coins and bills from least to greatest value, and then from greatest to least value. They should discover that counting from greatest to least value is easier.
  • Why is 30 minutes after the hour also called half past the hour?
    Visual models are the easiest way to answer this question. Display a clock showing time to the hour. Move the minute hand all the way around the clock.Ask: How many minutes are in 1 hour? (60) Move the minute hand halfway around the clock.Ask: How many minutes are in half an hour? (30 minutes) Draw a circle on the board and shade the right half to represent 30 minutes.
  • How do I know what time it is when the hour hand is between two numbers on the clock?
    When students learn to tell time, it is important that you focus their attention on the position of both hands. Point out to them that when the hour hand is halfway between two numbers, the time is half past the hour of the first number. When the hour hand is less than halfway between two numbers, the time is closer to the hour of the first number. And when the hour hand is more than halfway between two numbers, the time is closer to the hour of the second number. Give your students several examples to reinforce this concept.

Houghton Mifflin Math Grade 3