Ray's New Intellectual Arithmetic · Lesson XLVII · Unit 6: Money, weights and measures
47. United States money
Goal: Your child knows the table by heart and changes quantities to larger and smaller units.
You'll need
- The book page
- Real measures or coins if you have them
What's in the book
The table: 10 mills make 1 cent; 10 cents, 1 dime; 10 dimes, 1 dollar; 10 dollars, 1 eagle. Then problems that change to smaller units (multiply) and to larger units (divide).
The lesson, step by step
Warm up
Ask three or four problems from the last lesson again, out of order. Your child answers and says why.
Show the reasoning
SayIn 1 cent there are 10 mills, so in 2 cents there are 2 times 10, or 20 mills.
And going up: 20 dimes are as many dollars as 10 is contained in 20, which are 2.
Mills and eagles are no longer used, but the reasoning is the same for any units.
Work the problems aloud
Read each problem on the page aloud. Your child answers, then explains in a full sentence, the way the book's model solutions do. The problems go like this:
How many mills are in 2 cents?
How many cents are in 2 dollars?
Two hundred cents are how many dollars?
Ask “Why?”
After each answer ask “Why?” or “How do you know?” Ray's wants the reasoning said aloud, not just the number. If your child stalls, go back to the model and say the first half of the explanation together.
Wrap up
Pick the two problems that were hardest today. Tomorrow, start with those as the warm-up.
Afterwards
Do the rest of the lesson's problems over the next day or two, a few at a time. Move on when your child can explain them without help.
Answers to the book's problems
1) 20 mills. 2) 30, 40 … 90 mills. 3) 20 … 90 cents. 6) 200 cents. 8) 2 dimes. 11) $2.
Worked out for this site from the scan. If a number in your copy differs, trust the book. Every answer is in Ray's own Key ↗.