Understand a fraction 1/b as the quantity formed by 1 part when a
whole is partitioned into b equal parts; understand a fraction a/b as the quantity formed by a parts of size 1/b.

Standard:

Math.3.NF.2a or 3.NF.A.2.A

Description:

Represent a fraction 1/b on a number line diagram by defining the
interval from 0 to 1 as the whole and partitioning it into b equal
parts. Recognize that each part has size 1/b and that the endpoint
of the part based at 0 locates the number 1/b on the number line.

Standard:

Math.3.NF.2b or 3.NF.A.2.B

Description:

Represent a fraction a/b on a number line diagram by marking off
a lengths 1/b from 0. Recognize that the resulting interval has size
a/b and that its endpoint locates the number a/b on the number line.