Parent Guide — K.NBT.A.1
Kindergarten Math · Number & Operations in Base Ten
What this standard means
Your child learns that teen numbers (11–19) are made of ten ones plus some more ones.
Example: 18 = 10 + 8 — one group of ten and 8 extras. They show this with objects, drawings, and equations.
Why it matters at home
- Bundle 10 crayons with a rubber band + loose ones
- Egg carton ten-frame + extra counters for 14
- “Teen” talk: fourteen = ten and four
- Drawing a ten-rod and ones
- Packing: full sleeve of 10 plus leftover stickers
Connected standards
- Builds on:
- `K.CC.A.1` — counting by tens and knowing teens in the sequence
- `K.OA.A.4` — partners of 10 (comfort with “ten and …”)
- `K.OA.A.3` — composing/decomposing smaller numbers
- Connects within grade:
- `K.CC.A.3` — writing teen numerals
- `K.OA.A.1` — recording 10 + ones with equations
- Leads to:
- `1.NBT.B.2` — tens and ones for all two-digit numbers
- `1.NBT.C.4` — add within 100 using place value
- `1.NBT.A.1` — extend counting and numerals past 19
Try these together (this standard)
1. Build 15 as a ten and some ones. Write an equation. 2. Show 10 + 7. What teen number is that? 3. Decompose 19: how many ones with the ten?
Problems that show the connections
1. (Uses K.OA.A.4) First fill a ten-frame, then add 3 more to make 13. 2. (Uses K.CC.A.1) Count by tens to 10, then count on by ones to 16. 3. (Uses K.CC.A.3) Write the numeral for “ten and five.”
How you can help
- Always show a visible bundle of 10 — don’t only say “teen”
- Say both “sixteen” and “ten and six”
- Watch teen reversals in writing (61 for 16) — address gently
- Use equations: 14 = 10 + 4
- Keep the range 11–19 only for this standard
- Connect to fingers: two hands = ten, then extras
Answer key
1. 15 = 10 + 5 2. 17 3. 9 ones with the ten (19 = 10 + 9) 4. 13 5. 10, then 11…16 6. 15