Page 29 - NUMINO TG_4A

Challenge Number Pyramids
jOb ective Read and write 8-digit numbers.

1. Textbook Instructions Challenge Number Pyramids

1. Students will fill in the missing product in 1 . Fill in the blank. Write the number in word form.
the number pyramid and write the word form
of that number. a.
1a. 2 9 = 18
First have the students find the pattern in the
given multiplication sentences. 22 9 = 198
Ask them to look for the relationship and 222 9 = 1,998
pattern in the factors and products. 2,222 9 = 19,998
Factor: The number of 2s increases by 1 in
2,222,222 9 = 19,999,998
one factor, and the other factor is
always 9. The number of nines increases by 1.
Product: The number of 9s in the middle of
Word form: nineteen million, nine hundred ninety-nine thousand,
the product increases by 1. nine hundred ninety-eight.
The number of 9s in the product is one less
than the number of 2s in the factors.
The missing product can be found in the
following way:
There are seven 2s, so the number of 9s in
the product is six.
2,222,222 9 19,999,998
Write the number in word form.
nineteen million, nine hundred ninety-nine
thousand, nine hundred ninety-eight

10

2. Build Understanding

Using a place value chart
A place value chart can be used to write the word form of 19,999,998.

Millions Thousands Ones
Tens Tens
Tens Ones Hundreds 9 Ones Hundreds Ones
1 9 9 9 9 9 9

nineteen million, nine ninety-nine thousand, nine ninety-eight
hundred hundred

012 NUMINO Teacher s Guide