Subtract by removing matching pieces
This is a self-guided version of the lesson: rebuild the meaning, reconnect it to the rule you may remember, then test whether the idea is genuinely secure.
Subtraction is the same piece-size issue
5/7 − 2/7 means remove two seventh-pieces from five seventh-pieces. Three sevenths remain.
Again, the denominator does not change because the piece size does not change.
Rename before removing
For 3/4 − 1/2, rewrite the half as 2/4. Then 3/4 − 2/4 = 1/4.
If you are tempted to manipulate symbols first, ask what physical piece you are trying to remove. The mismatch becomes obvious.
Money gives an immediate sense check
75p − 50p = 25p and 75¢ − 50¢ = 25¢. That is exactly 3/4 − 1/2 = 1/4 of £1 or $1.
Use this to check whether a symbolic answer is plausible.
Move on when…
You can subtract matching pieces, rename a familiar fraction before subtracting, and use addition to check the result.
Use the interactive learner lesson when useful
The learner page contains the visual examples and interactive practice. Use it as a tool rather than as a different course: return here when you want the explanation, diagnostic questions and bigger-picture connections.
Open matching learner lesson →