Counting by Tens with numbers
10, 20, 30, 40, 50, 60, 70, 80, 90
Counting by Tens with words
ten, twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, one hundred
Number Patterns when counting by Tens
When you count by tens the numbers create a pattern. All the numbers end with a zero. The first digits are just like the numbers when you count (1, 2, 3, 4, 5, etc.). This pattern gives the numbers 10, 20, 30, 40, 50, etc.
found from: http://www.aaamath.com/k4c_cox1.htm
I think you would do 39 x 4 because if the SQUARE brick has sides 1 foot long, you count up the sides and get 4 feet. She has 29 square feet of patio bricks so you would multiply 39 x 4. I don't know if this is correct. Hopefully I helped!
