Last updated 2026-09-18. Written by the TernQuest team. This guide is for parents of 1st graders (and late kindergartners) who want to help with addition facts without turning the kitchen table into a drill hall.
What does "addition within 20" mean in 1st grade?
Direct answer: It means adding any two numbers whose sum is 20 or less, such as 7 + 6 or 9 + 9. By the end of 1st grade, children are expected under the California Common Core standards to add and subtract within 20 and to be fluent within 10, though your school's pacing may differ. Fluent means the answer comes from a strategy or from memory, not from counting every finger.
The full picture of what a 1st grader is expected to know is in our 1st grade math skills checklist. This post covers just one line of it, because it is the line that causes the most worry at home.
Quotable version: "Fluency within 20 is not speed; it is having a strategy for every fact and using it without thinking."
Why teach strategies instead of memorizing the facts?
Direct answer: Memorizing a table of facts without strategies tends to stall around the harder sums (7 + 8, 6 + 9) because there is nothing to fall back on when memory blanks. Strategies give the child a way to rebuild any fact in a second or two, and repeated use of the strategy is what eventually turns it into memory. Memorization is the result, not the method.
There is a second reason. The strategies below are the same ones a child will reuse for subtraction within 20, for adding within 100, and later for mental math with larger numbers. The make-ten idea in particular is the seed of place-value thinking, which we explain in number bonds and the make-ten strategy.
Strategy 1: How does counting on work?
Direct answer: Start from the bigger number and count up by the smaller one. For 8 + 3, the child says "eight" and then counts "nine, ten, eleven." It replaces counting all (starting from one) and is usually the first strategy children learn.
How to teach it
- Say the bigger number out loud, then tap the smaller number on fingers while counting up.
- Practice "turn it around" first: 3 + 8 is the same as 8 + 3, so always start from 8.
- Keep the smaller number at 1, 2 or 3. Counting on by 6 is slow and error-prone; those facts belong to a different strategy.
When to move on
When your child can count on by 1, 2 or 3 from any number up to 20 without recounting from one, they are ready for doubles.
Strategy 2: What are doubles and why do they matter?
Direct answer: Doubles are facts where both addends are the same: 1 + 1 through 10 + 10. Children tend to learn them quickly because they are rhythmic and because the world is full of pairs (two hands, egg cartons, dice). Once known, doubles become anchors for the near-doubles strategy.
| Double | Everyday picture |
|---|---|
| 1 + 1 = 2 | Two eyes |
| 2 + 2 = 4 | Wheels on a car |
| 3 + 3 = 6 | Legs on an insect |
| 4 + 4 = 8 | Legs on two chairs |
| 5 + 5 = 10 | Fingers on two hands |
| 6 + 6 = 12 | Eggs in a carton |
| 7 + 7 = 14 | Days in two weeks |
| 8 + 8 = 16 | Legs on two spiders |
| 9 + 9 = 18 | Two baseball teams |
| 10 + 10 = 20 | Fingers and toes |
Chant them, clap them, put them on the fridge. The pictures are not decoration; a child who is stuck on 7 + 7 can picture two weeks of calendar squares.
Strategy 3: How do near doubles work?
Direct answer: A near double is a double plus or minus one. For 6 + 7, the child thinks "6 + 6 is 12, and one more is 13." It converts a hard fact into an easy fact plus a step, and it covers a large share of the awkward sums in the teens.
How to practice
- Show two numbers that are one apart. Ask "which double is hiding in here?"
- Say the double first, then the adjustment: "double 6, plus 1."
- Later, extend to doubles plus two (5 + 7 is double 5 plus 2, or double 6).
Strategy 4: How does make ten work?
Direct answer: To add 8 + 5, take 2 from the 5 to make the 8 into 10, then add the leftover 3: 10 + 3 = 13. It works because any number is easy to add to 10, and it relies on knowing the pairs that make 10 (8 and 2, 7 and 3, 6 and 4, 5 and 5, 9 and 1).
How to teach it with a ten frame
A ten frame is a grid of two rows of five. Put 8 counters in one frame and 5 in another. Ask the child to fill the first frame's empty spaces: they move 2 over, the first frame is full (ten), and 3 remain. Read it as "ten and three, thirteen." Do this with real objects several times before asking them to picture it.
Make ten is the strategy for the facts counting on cannot reach: 8 + 5, 9 + 6, 7 + 6, 8 + 7. If the number bonds of 10 are shaky, fix those first; the number bonds post has the sequence.
Strategy 5: How do known facts lead to new facts?
Direct answer: If a child knows 5 + 5 = 10, they can reason that 5 + 6 = 11 and 5 + 4 = 9. If they know 10 + 4 = 14, they can reason that 9 + 4 = 13 (one less). This is the strategy that ties the others together, and it is the sign that a child understands addition rather than reciting it.
Prompts that build it:
- "You know 6 + 6. What is 6 + 7?"
- "You know 10 + 3. What is 9 + 3?"
- "You know 8 + 2 = 10. What is 8 + 3?"
What does a 2-week practice plan look like?
Direct answer: One strategy at a time, a few minutes a day, with a game or real objects rather than worksheets where possible. Two weeks is enough to introduce all five strategies; mastery of the full set takes the school year, and that is normal.
| Day | Focus | What to do (about 5 minutes) |
|---|---|---|
| 1–2 | Counting on | Roll a die, add it to a number card 5–15, count on aloud |
| 3–4 | Doubles | Chant the doubles table; point to the everyday pictures |
| 5 | Mixed | Sort fact cards into "counting on" and "doubles" piles |
| 6–7 | Near doubles | Two numbers one apart; say the hidden double, then adjust |
| 8–9 | Make ten | Ten frames with counters; 8 + 5, 9 + 4, 7 + 6 |
| 10 | Mixed | Sort cards into all four strategy piles |
| 11–12 | Known facts | "You know X, so what is Y?" prompts |
| 13 | Child's choice | Let them pick the strategy for each card and explain why |
| 14 | Check | Ask 10 mixed facts; note which strategy they used, not how fast |
The last day is a check, not a test. Write down which facts still need counting-all and put those on the fridge for week three.
Is fluency the same as speed?
Direct answer: No. Fluency means the child gets the right answer, gets it efficiently, and can get it more than one way. A timer measures none of those on its own, and for some children it produces exactly the freeze that makes them look less fluent than they are. Practice strategies until the answers come easily and let speed be the result.
If your child already dreads math time, read math anxiety in kids: signs and what to do before adding any more practice. The order matters: comfort first, then facts.
TernQuest's 1st grade map covers addition within 20 with hint-based games and no countdown clock, and the weekly report shows which facts a child still counts on. It is not the right tool for the first week of a brand-new strategy, though: ten frames and counters on the table teach make ten better than any screen, so use a game only once the idea has landed. A broader view of what fluency is and is not lives in math fact fluency: what it is and how to build it.
Related reading
- Number bonds and the make-ten strategy — the prerequisite for strategy 4.
- 1st grade math skills checklist (2026) — where addition within 20 fits among the year's other skills.
- Math fact fluency: what it is, what it isn't — the longer argument against speed drills.
Next step
Once a strategy has landed with counters, let your child practice it in TernQuest, which is free to start for one child and needs no app install. The weekly report will tell you which facts still need the ten frame.