Definition
Same-whole condition
The same-whole condition means fractions are compared using wholes of equal size.
What it means
One half is not a fixed amount by itself. Half of a large sheet can be more than three quarters of a small sheet. Before comparing fractions, check that “one whole” means the same-sized thing on both sides.
Remember it
Fractions travel with their wholes.
Example
Mina drinks 1/2 of a 600 mL bottle, which is 300 mL. Leo drinks 3/4 of a 200 mL bottle, which is 150 mL. Although 3/4 > 1/2 as fraction numbers, Mina drinks more because the bottle wholes differ.
Watch for
The condition concerns the size of the reference whole, not whether two pictures have the same shape.
Common mix-up
Comparing fraction numbers is different from comparing actual amounts taken from unequal wholes.
Exact meaning
The same-whole condition requires fraction comparisons to refer to the same whole, or to quantities converted to one common unit. A fraction gives a relative part, so its actual amount changes when the whole changes.