Concept 3 of 5
Shift Codes: Move One Step
Today's big idea
Bump each letter one step
A→B, B→C — every letter moves 1.
How it works
👀 What's going on?
Here is a spy trick: write a word, then bump every letter one step along the alphabet. CAT quietly becomes DBU, and only a friend who knows the trick can turn it back.
💡 Here's the trick
In a shift code every letter moves the same number of steps forward. In our code the step is 1: A→B, B→C, C→D. To decode, you simply step back one instead.
- 1.Take the first letter and move it 1 step forward (or back, to decode).
- 2.Do exactly the same to every other letter.
- 3.Read the new letters together.
✍️ Try it
- 1.Code the word CAT (move each letter forward 1).
- 2.The code word is CBU. What is the real word? For CAT: C→D, A→B, T→U, so the code is DBU. For CBU, step back one: C→B, B→A, U→T, so the word is BAT.
⚠️ Watch out
Move every letter, not just the first. If you shift C to D but leave A and T alone you get DAT, which is wrong. The same step goes on all of them.
See it in action
⚡ Time to play!
Slide each letter forward 1 step. Tap a letter to move it on by one.
CODE THE WORD “BUS” ( +1 )
Quick check
✅ VERIFICATION
In a +1 shift code, what is the code for the word BAT?
⚡ Finish the activity above first to answer.
Keep going!
Up next: Picture Puzzles
Solve the simple line first.