Question

How many 250 g weight can make one and a half kg?

Answer 1

We know that 250 g is the same as $\frac{1}{4}$ kg or a quarter of a kg.
Four $\frac{1}{4}$ kg weights make a kilogram.
Two $\frac{1}{4}$ kg weights make half a kilogram.

Thus, $4+2=6$ weights of 250 g make one and a half kg.