Mental Math with 11: Addition and Subtraction Tricks

What is the quick method to add 11 to a number like 46?

• Add 10 and then add 1

• Add 12 and subtract 1

• Add 11 directly

• Subtract 10 and add 21

How do you quickly subtract 11 from a number like 46?

• Subtract 10 and then subtract 1

• Subtract 12 and add 1

• Subtract 11 directly

• Add 10 and subtract 21

If you add 11 stars to a constellation of 34 stars, how many stars are there in total?

• 44

• 45

• 46

• 47

After 11 asteroids crash into a planet from a group of 52, how many asteroids remain?

• 41

• 42

• 40

• 43

What is the result of adding 11 to 52 using the quick method?

• 65

• 64

• 63

• 62