MathGrade 4ages 9–10
🧩 Add like fractions
A child who adds 1/4 + 1/4 and gets 2/8 is treating the fraction like two whole numbers stacked on top of each other, rather than seeing the denominator as a description of how a whole was already cut.
Try this lesson freeNo card needed. The first lesson is free.
Download on the App StoreWhat your child learns
- The denominator says how many pieces the whole was cut into.
- The numerator says how many of those pieces we took.
- When you take another piece, only the numerator grows.
- The denominator moves only if the cake is recut, and that did not happen.
The mistake most kids make here
Adding the numerator and the denominator both.
Try one question
A quarter and a quarter. How much is that?
1/4 + 1/4
- 1/2
- 2/8
- 1/8
Answer
1/2 — Yes. Two quarters is a half.
How Maya teaches it
Your child tells Maya what they did in class. She teaches this topic at her desk, asks questions with tappable answers, and when the answer is wrong she explains why that answer was tempting instead of saying “try again”. She remembers what did not land and comes back to it.
Your child has it when they can: How much is a quarter and a quarter, and why does the denominator not move?
How to help at home
It looks consistent to add both the top and bottom numbers, the way you'd add any two-part quantities — but the denominator isn't a quantity being added, it's a label for how many equal pieces the whole was cut into.
Cut a paper circle or a pita into four equal pieces. Take one piece for the first quarter, then another piece for the second quarter, and push them together. Count how many quarter-pieces you're holding — two — out of the four the whole was cut into. That's 2/4, which is the same as a half, not 2/8.
When 1/4 + 1/4 comes out as 2/8, ask: "did we cut the pita into more pieces just now, or did we just take another piece from the same cutting?" Nothing re-cut the pita into eighths — only the count of pieces taken changed.
A sign they've got it: they can explain that the denominator only changes if the whole itself gets cut differently, not just because you're adding two fractions together.
Questions parents ask
- Why does my child add the denominators when adding fractions?
- It can seem like the consistent thing to do, treating the fraction as two separate numbers stacked together. But the denominator describes how many pieces the whole was cut into, which doesn't change just because you're combining pieces from that same cutting.
- How do you add fractions with the same denominator?
- Add only the numerators (the top numbers) and keep the denominator the same. 1/4 + 1/4 = 2/4, because you now have two of the four equal pieces.
- Is 2/4 the same as 1/2?
- Yes. Two quarter-pieces put together take up exactly the same space as one half-piece, even though they're written differently.
- How does Maya teach adding fractions with the same denominator?
- Maya has the child physically combine pieces cut from the same whole, so it's clear only the count of pieces taken is growing, not the size of each piece or the number of pieces the whole was cut into.
No card needed. The first lesson is free.
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