UNIT 13 // SESSION B // MASTER WHEN READY
Rows and columns
Name:Date:
An array is dots in neat rows and columns. Count by rows, then by columns. The total is the same either way.
1Fill in the totals.
3 rows of 6 → by rows: 6, 12, Total
4 rows of 5 → Total
2 rows of 8 → Total
5 rows of 5 → Total
3 rows of 10 → Total
6 rows of 4 → Total
2Draw an array of 3 rows with 6 in each row.
Now count it by COLUMNS. How many columns? How many in each? Total
3Same total, different shape. Draw 12 dots as 2 rows of 6, then as 3 rows of 4.
What did you notice?
4Word problems.
aThe egg carton has 2 rows of 6. How many eggs fit?
bA chocolate bar has 4 rows of 5 squares. How many squares?
1. 18 = 18; 20; 16; 25; 30; 24 2. 6 columns, 3 in each, 18 3. both make 12 4. a 12, b 20