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Number Explorer (Grades K–5)
Light up patterns on a hundreds chart and build numbers with blocks. You do the noticing.
Roji asks
- Expanded form
- Word form
For teachers and families
Number Explorer gives students a hundreds chart and base-ten blocks to think with. It lights up patterns and asks what the student notices; it does not hand out answers. Turn on Try it first to have students predict a pattern before they see it.
- Grades K–2: skip counting by 2s, 5s and 10s, even and odd, tens and ones.
- Grades 3–5: multiples, factors, primes, common multiples, thousands, tenths and hundredths.
- Private: nothing is typed in but numbers, and nothing is saved. Closing the page clears it.