Discover a trick right here that may assist you multiply a repdigit quantity lower than 100 by a single digit quantity in lower than 2 seconds so long as you recognize your multiplication desk.

What’s a repdigit quantity? A repdigit quantity is a quantity whose digits are the identical. For instance, 55 and 77 repdigit numbers.

What’s a single-digit quantity? A single-digit quantity is a quantity that has only one digit. For instance, 4 and eight are single-digit numbers.

The trick to observe is proven within the 3 examples under

Instance #1

44×9 = ?

Step 1: Multiply 4 by 9 to get 36. Write 36 down with an area between 3 and 6

Step 2: Add 3 and 6 to get 9

Step 3: Put 9 between 3 and 6.

44×9 = 396

Instance #2

88×5 = ?

Step 1: Multiply 8 by 5 to get 40. Write 40 down with an area between 4 and 0

Step 2: Add 4 and 0 to get 4

Step 3: Put 4 between 4 and 0.

88×5 = 440

Instance #3

99×9 = ?

Step 1: Multiply 9 by 9 to get 81. Write 81 down with an area between 8 and 1

Step 2: Add 8 and 1 to get 9

Step 3: Put 9 between 8 and 1.

99×9 = 891