CCSS.Math.Content.1.NBT.B.2a
The standard
10 can be thought of as a bundle of ten ones — called a "ten."
Common Core State Standards for Mathematics
What this standard means
Students need to see ten ones as one group called a ten. They should build, count, and describe 10 single objects as 1 ten, not just count from 1 to 10. They also need to connect this idea to base-ten blocks, ten-frames, and written numbers like 10.
Mastery looks like a student making a group of ten, naming it as 1 ten, and explaining that it still equals 10 ones. Students often get stuck thinking the bundle is “one” without remembering it means 10 ones, or they count loose objects but do not group them.
Ways to teach it
- Give students 10 craft sticks and a rubber band, then have them bundle the sticks and label it “1 ten.”
- Ask, “How can one bundle be the same as ten sticks?” and have students draw and write their answer.
- Show a ten-frame with 10 counters and ask students to complete: “10 ones is the same as ___ ten.”
- Connect to dimes and pennies by showing that 10 pennies can be traded for 1 dime.
Plan a lesson for CCSS.Math.Content.1.NBT.B.2a
Generate a complete lesson plan aligned to this standard, with objectives, activities, and materials. Free, no account needed.
Related standards
- CCSS.Math.Content.K.NBT.A.1
Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decompositio...
- CCSS.Math.Content.1.NBT.B.2b
The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
- CCSS.Math.Content.2.NBT.A.1a
100 can be thought of as a bundle of ten tens — called a "hundred."
- CCSS.Math.Content.1.NBT.B.2c
The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).