Multiplying by 11 means adding a number to itself 10 times. A strong knowledge of these facts makes solving larger problems faster and easier.
Think of it as taking the other number, putting it in the tens and ones place, and then adding it together. For 11 × 4, think "4 and 4" to get 44.
To build fluency, you must know all combinations from 1 through 12. Here is the complete set of facts.
Notice the clear pattern from 1 through 9. For 10, 11, and 12, commit these three facts to memory: 110, 121, and 132.
Knowing multiplication facts allows you to solve real-world problems quickly. Look for phrases like "groups of," "rows of," or "11 times as many."
When you see a problem involving 11, identify the other number you are multiplying by. Use your known facts or the break-apart strategy to find the total.
Use patterns, repeated practice, and related facts to build quick recall of all multiplication facts with 11.
Consistent practice is the best way to build fluency. Try writing the facts from 11 × 1 to 11 × 12 in order and say them aloud.