Crack the code

Find the digit, 0 through 9, that each letter represents. Replace the letter with that digit to create a valid equation.

  • Each digit may only be used for one letter.
  • Letters always represent the same digit throughout the equation. If the letter M represents 3, then all places where you see M you can put the number 3.
  • The first letter in each word will not be zero (0).
  • Check your progress by clicking the "Check answer" button. It will tell you which of your selections are right and which are wrong, so you can correct yourself before you go too far down the wrong path.
Decoded Letters:
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
You are correct!

Helpful hints

  • In many cases, the answer of an addition problem is one digit longer than the addends (the numbers added). For example: XX + YY = ZZZ. In such a case, if there are only two addends, the first digit of the answer will always be 1.
  • Don’t forget about “carrying” a digit into the next column. Carrys aren’t shown on the puzzle, but you need to account for them when solving. Remember, a carried digit will always be less than the number of addends in the problem. For example, if you’re adding two numbers together, your carry (when you have one) will always be 1; if you’re adding three numbers, your carry could be 1 or 2.
  • Look for places where you can make a logical deduction — for example, when you can establish a relationship between two letters, like B = A + 1. That can help narrow down your choices.
  • You may find it helps to make a grid to solve these puzzles. List the letters of the puzzle along one axis and the numbers 0-9 along the other. As you rule out possible numbers for each letter, cross them off on the grid.
  • If you’re having trouble getting started, give yourself a head start — pick one letter and guess your way through the possible numbers using the “Check answer” button. Then try to solve the puzzle with one letter filled in. As you get better at this type of puzzle, see if you can solve them without the head start.
  • Finally, here’s a YouTube video of a math teacher walking you through one of these puzzles. Watch and learn!
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