Whole amount
20
Total parts (a + b)
4
One part is worth
5
Ratio
3 : 1
means
3 + 1 = 4
equal parts.
One part = whole ÷ parts =
20
÷
4
=
5
Ratio:
3 : 1
2 : 3
1 : 1
5 : 2
★ Highlight one part
↺ Reset
Drag the
brass dot
on the right to change the
whole amount
. The bar always splits into equal parts — first find what
one part
is worth, and the rest is easy.