Time and money
A clock face repeats twice a day and a dime is smaller than a nickel. How do you read the time, count money, and work with both?
Where you are 13 inside
What this area is about
Time and money are the two measurements children handle every day. Time is read from clocks and grouped into units that go by sixties and twenty-fours, not tens. Money is counted by worth, not by how many coins, and is written as a decimal. These are two separate strands that share an area.
How these fit together
Reading clocks. Telling time, then to the nearest five minutes. Morning and afternoon and twenty four hour time say which half of the day a time is in.
Units of time. Units of time nest seconds up to years; calendars and dates group days into weeks, months and years.
Working with times. Elapsed time finds how long from one time to another; time zones shift a time from one place to another.
Money. Money gives each coin and bill its worth. Counting mixed coins and money story problems add and subtract amounts. Money as decimals writes four dollars and seventy-five cents as one decimal, \text{\textdollar}4.75, and currency exchange trades one country’s money for another at a rate.
A path through it
Time: telling time first. Then five minutes, morning and afternoon, units of time and elapsed time, each building straight on telling time. Calendars follow units of time; twenty four hour time follows elapsed time; time zones come last.
Money: money first. Mixed coins lead to story problems; decimals lead to currency exchange, which also needs proportions.
Next: flow rate uses units of time.