Continue Counting Across One Hundred
Write the supplied starting numeral.
About 15 minutes, plus any extended practice
Open lesson 1Count to 120 and Add with Place Value
Continue through one hundred and use tens and ones when adding or subtracting.
Before you begin
- Build and compare tens and ones; add or remove one ten.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Exchange Ten Ones When Adding
Separate the two-digit addend into tens and ones.
About 15 minutes, plus any extended practice
Open lesson 2Add a Multiple of Ten
Count the starting tens and the added tens.
About 15 minutes, plus any extended practice
Open lesson 3Subtract Whole Tens from Whole Tens
Represent both supplied amounts as tens groups.
About 15 minutes, plus any extended practice
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.
Topic references
- Common Core State Standards, mathematics: 1.NBT.A.1 — Continue through one hundred and use tens and ones when adding or subtracting.
- Common Core State Standards, mathematics: 1.NBT.C.4 — Continue through one hundred and use tens and ones when adding or subtracting.
- Common Core State Standards, mathematics: 1.NBT.C.6 — Continue through one hundred and use tens and ones when adding or subtracting.
These references informed the topic selection. They do not certify complete standards alignment.