Numbers in written form

The  exercise appears under the 4th grade (U.S.) Math Mission. This exercise practices viewing numbers in written form.

Types of problems
There are two types of problems in this exercise:
 * 1) Match the written form and expanded form that describe the same number.: This problem has a chart with written and expanded forms of numbers and user is asked to drag the panels to match them.
 * 2) What is ___ in words?: This problem has a number and user is asked to find what it is in words.

Strategies
Basic knowledge of place value is required for this exercise.
 * 1) It could help make finding numbers in written from easier if user breaks their number into parts.