Ray's New Practical Arithmetic · Arts. 50–53 · Unit 6: United States Money
26. Compound numbers and U.S. money
Goal: Your child explains a compound number and reads and writes sums of money in dollars, cents and mills.
You'll need
- The book
- A few real coins and bills
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
Compound numbers and reduction defined, the table of United States money (mills, cents, dimes, dollars, eagles), a table of coins, and how to write and read money with lists to practice.
The lesson, step by step
Warm-up
Ask: How many cents in a dime? In a dollar? How many dimes in a dollar?
Compound numbers
Read:
A compound number is made up of two or more concrete numbers of different denominations
Reduction is the process of changing the denomination of a number without altering its value.
Say5 yards 2 feet is a compound number. Changing 5 yards to 15 feet is reduction.
The money table
Read the table: 10 mills make 1 cent, 10 cents 1 dime, 10 dimes 1 dollar, 10 dollars 1 eagle.
The mill is not coined. It is used only in calculations.
Note for you: the eagle was a $10 gold coin, and mills still turn up in gas prices (the 9/10 of a cent) and property tax rates.
Writing money
Show that cents take two places after the point and mills a third: $12.178 is twelve dollars seventeen cents eight mills.
Write the first item together:
Twelve dollars seventeen cents eight mills.
Independent practice
Your child writes the rest of the "to be written" list and reads the "to be read" list aloud.
Wrap-up
Ask: How do you write five dollars and five cents? ($5.05.) Fifty cents? ($0.50 or 50 cents.)
Tip
The table of coins lists coins of 1877 (such as half dimes and three-cent pieces). Treat it as a bit of history; there's nothing to memorize.
Answers to the book's problems
Money to be written: $12.178; $6.066; $7.007; $40.535; $2.03; $20.022; $100.10; $200.02; $400.018.
Worked out for this site from the scan. If a number in your copy differs, trust the book.