Fraction rules
Six sentences that decide whether a fraction answer is right before any arithmetic happens. Print it for the weeks when fractions are new and the rules keep swapping places.
Reference chart
Fraction rules
Adding and subtracting
- 25+15=35Bottoms match: add the tops, keep the bottom.
- 12+13=56Bottoms differ: recut both, then add. Bottoms are never added.
Multiplying and dividing
- 23 × 34=612=12Multiply straight across — you are taking a part of a part.
- 12÷14=2they fit twiceDivide by flipping the second one over. How many fit inside?
Tidying the answer
- 68=34Simplify: fewer, bigger pieces covering the same amount.
- 1+1+14=9quarters — 94, or 2 14Count every piece: two wholes and a quarter is nine quarters.
What's on this chart
The fraction wall shows a child what a fraction is; this chart tells them what to do with one. They are different problems. A child can understand perfectly well that 1/2 is bigger than 1/3 and still write that 1/2 + 1/3 is 2/5, because the picture and the procedure are stored in different places and only the procedure is being asked for on the page.
Why this chart helps
That very mistake is why the second rule is worded the way it is. Adding the bottoms is the single most common fraction error there is, and it is not carelessness — it is what every other operation the child has met so far would suggest. The chart says plainly that the bottoms are never added, and having that sentence in view is worth more than being corrected on it again.
More printable charts
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Print Find the operation you have, and the example shows where the rule comes from. - Scientific notation
Print Move the decimal point to a number between 1 and 10, then count the places as the power.