Ray's New Practical Arithmetic · Art. 11 · Unit 1: Numeration
4. Writing large numbers
Goal: Your child writes numbers in the millions from words, filling empty orders with ciphers.
You'll need
- The book
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
How to write numbers in the Arabic system, period by period, then a long list of numbers to be written, from thousands up to many periods.
The lesson, step by step
Warm-up
Name the periods in order from the right: units, thousands, millions, billions. Ask: How many figures in each period? (Three.)
The rule
Read the rule together.
Begin at the left, and write each period as a number composed of hundreds, tens, and units
SayEvery period except the first one on the left gets all three figures, even if some are zeros.
Work an example
Say aloud: four million, thirty thousand, five. Write it together, period by period: 4 | 030 | 005, so 4030005.
Point to the zeros: they fill the empty orders.
Guided practice
Do the first items of the list together:
Two thousand; thirty thousand; four hundred thousand.
Ask after each: Which period is this number in? Are all the empty orders filled?
Independent practice
Your child writes the next several items of "Numbers to be written" in the notebook. Stop after about 10 items if they're tiring; finish the rest another day.
Check
Read each written number back aloud, period by period. If it doesn't match the words, look for a missing zero.
Wrap-up
SayHow do you write one thousand and one? (1001.) Ten thousand and ten? (10010.)
Afterwards
Finish the list over the next few days, a handful at a time.