Introduction to Multiplication — Answer Key
Part A: Sort the Words
Sort each word or number into the correct category box.
1. Sort each sentence into the correct category.
Describes an Array
3 rows of 24 rows of 52 rows of 6 Does Not Describe an Array
5 minus 27 plus 110 take away 3 An array has equal rows and columns, so 'rows of' phrases all describe arrays. Adding and subtracting do not make rows and columns, so those belong in the other group.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. An array with 2 rows and 4 columns has 8 items in all.
To find the total in an array, multiply rows by columns: 2 x 4 = 8. You can also count 4 + 4 = 8.
2. 3 rows of 5 means 3 x 5.
The first number tells how many rows and the second tells how many are in each row. So 3 rows of 5 becomes 3 x 5.
3. An array with 4 rows and 3 columns has 12 items in all.
Multiply rows by columns: 4 x 3 = 12. You can also add 3 + 3 + 3 + 3 to reach 12.
4. 5 rows of 2 equals 10.
Five rows with 2 in each row is 2 + 2 + 2 + 2 + 2, which equals 10.
5. An array with 2 rows and 3 columns shows 2 x 3.
The first number in 'rows x columns' is the number of rows. Two rows and three columns is written as 2 x 3.
Part C: True or False?
Read each statement. Circle True or False.
1. An array with 3 rows and 3 columns has 9 items.
True False
Three rows of 3 makes 3 + 3 + 3 = 9. Multiplying 3 x 3 gives the same total of 9.
2. 2 rows of 5 is the same as 5 rows of 2.
True False
2 x 5 and 5 x 2 both equal 10, so swapping rows and columns gives the same total. The arrays look different but hold the same number of items.
3. An array with 4 rows and 2 columns has 6 items.
True False
4 rows of 2 equals 4 x 2, which is 8. The number 6 would come from 3 x 2 or 2 x 3 instead.
4. 1 row of 7 equals 7.
True False
One row of 7 items is just 7 items in a line. Multiplying 1 x 7 always gives 7.