Use compensation to add

~9 min

Adjust one number to make the problem easier, then adjust back.

Make a friendly 10

Make a friendly 10
  • A friendly number is easy to add, like a ten. You can change 9 to 10 to make adding easier.

A friendly number is easy to add, like a ten. You can change 9 to 10 to make adding easier.

💡 Look for a number that is 1 away from 10.