20 number talk prompts by grade
A number talk is ten to fifteen minutes of mental math: you show one problem, students solve it in their heads, and the class compares the different ways they got there while you write each strategy on the board. The point is the strategies, not the answer. Below are twenty prompts, grouped K–2, 3–5 and 6–8, each with exactly what to show, what to ask and the strategies to listen for.
Kindergarten to 2nd grade
1. Five dots in a flash
Show the card for three seconds, then hide it. Ask "How many dots? How did you see them?" Listen for "three and two", "four and one more" and "I saw the five on a die."
Grades K–1You need A card with five dots, three in a row and two belowUse Dot paper
2. Seven on a ten frame
Flash the ten frame with seven filled. Ask "How many? How many more make ten?" Listen for "five and two more" and "three empty, so seven."
Grades K–1You need A ten frame with seven countersUse Ten frames
3. Eight and six on two ten frames
Show eight on one frame and six on the other. Ask "How many in all?" Listen for moving two over to make ten and four (14), and for doubles: six and six is twelve, plus two.
Grades 1–2You need A double ten frame with eight and sixUse Double ten frames
4. Doubles, then near doubles
Write 6 + 6, take answers, then write 6 + 7 underneath. Ask "How can the first problem help with the second?" Listen for "it's one more than the double."
Grades 1–2You need The board
5. A make-ten string
Write one at a time: 9 + 4, then 9 + 6, then 8 + 5. Ask for answers and methods after each. Listen for taking one from the other number to turn 9 into 10.
Grades 1–2You need The board
6. Ten more, ten less
Point to 23. Ask "What is ten more? Ten less?" then try 47 and 80. Listen for "the tens digit changes and the ones stay the same" and "I moved down a row."
Grades 1–2You need The hundreds chart on the projectorUse Hundreds chart
7. Thirty-eight plus five
Write 38 + 5. After answers, draw the jumps students describe on an open number line: 38 to 40 is two, then three more is 43. Listen for breaking five into two and three.
Grades 2You need An open number line drawn on the boardUse Number line
3rd to 5th grade
8. Ninety-nine plus forty-seven
Write 99 + 47. Listen for "100 + 47 is 147, take away one" and for moving one from 47 to the 99. Ask which way was quickest and why the answers agree.
Grades 3–4You need The board
9. Sixty-three minus twenty-nine
Write 63 − 29. Listen for counting up from 29 to 30 to 63 (34), for subtracting 30 and adding one back, and for taking 20 then 9. Draw each one on a number line.
Grades 3–4You need An open number line drawn on the board
10. Twenty-five times twelve
Write 25 × 12. Listen for "four 25s make 100, and 12 is three fours" (300), for 25 × 10 + 25 × 2, and for halving and doubling to 50 × 6.
Grades 4–5You need The board
11. Eighteen times five
Write 18 × 5. Listen for halving 18 and doubling 5 to make 9 × 10, and for 10 × 5 plus 8 × 5. Ask whether halving and doubling always works, and why.
Grades 3–5You need The board
12. Three-quarters or five-eighths
Ask "Which is more, 3/4 or 5/8? How do you know without working it out on paper?" Listen for "3/4 is 6/8" and "each is that far from one whole."
Grades 3–5You need Fraction bars on the projectorUse Fraction bars
13. An array of dots
Show a six-by-eight array for ten seconds. Ask "How many dots? How did you count?" Listen for 6 × 8, for 5 × 8 plus 8, and for splitting it into two 3 × 8 halves.
Grades 3–4You need A six by eight array of dotsUse Array grids
14. One thousand minus three hundred sixty-eight
Write 1,000 − 368. Listen for counting up (368 to 400 to 1,000), for 999 − 367 so no regrouping is needed, and for subtracting the hundreds, tens and ones in turn.
Grades 4–5You need The board
6th to 8th grade
15. Fifteen hundredths of eighty
Write 0.15 × 80. Listen for a tenth of 80 (8) plus half of that (4) to make 12, and for 15 × 8 = 120 then dividing by ten. Ask how the two methods connect.
Grades 6–7You need The board
16. Three ninety-nine times six
Write 3.99 × 6. Listen for 4 × 6 = 24 minus 6 hundredths (23.94), and ask students where they might use this when shopping.
Grades 6–7You need The board
17. Negative seven plus twelve
Write −7 + 12, then 7 − 12. Ask what is the same and different about the two. Listen for jumping across zero and for "the distance between them is five."
Grades 6–7You need A number line on the projectorUse Number line
18. Two-thirds of twenty-seven
Write 2/3 of 27. Listen for "a third of 27 is 9, so two-thirds is 18" and for 27 − 9. Then try 2/3 of 28 and talk about why the answer isn't a whole number.
Grades 6–7You need The board
19. Forty-eight divided by one-half
Write 48 ÷ 0.5. Many students say 24 at first. Ask "How many halves are in one? In 48?" Listen for the answer 96 and for "dividing by a half is doubling."
Grades 6–8You need The board
20. Undo the equation
Write 3x + 4 = 25 and ask students to solve it in their heads. Listen for working backward: take off the 4 (21), then share it into 3 (7). Ask how they would check it.
Grades 7–8You need The board
Making it work
- Students show a quiet thumb on their chest when they have an answer, and extra fingers for each extra way they found. Nobody waves a hand, so nobody is rushed.
- Write every strategy on the board in the student's words, with their method drawn on a number line or an array. Don't name the strategy before they do.
- Take all the answers first, right or wrong, without saying which is right. Then ask a few students to explain, and let the class decide.
- Keep it to one problem or one short string of related problems. Ten to fifteen minutes is enough.
- Plan the problems so they invite a particular strategy, such as 99 + 47 for using a friendly number.
Questions teachers ask
- What is a number talk?
- A short daily routine where students solve a problem mentally and then share and compare their strategies. The teacher records each strategy so the class can see several ways to reach the same answer.
- How often should I do number talks?
- Many teachers do one most days at the start of math, for ten to fifteen minutes. A regular routine matters more than a long session, because students get used to explaining their thinking.
- What if a student gives a wrong answer?
- Write it on the board with the others, without comment. When students explain their thinking, the mistake usually shows itself, and the student can change their answer. That's a normal part of the talk.
- What do I do if nobody has a strategy to share?
- Choose an easier problem in the same family, or show a picture such as a ten frame or an array. Then ask a student to describe exactly how they counted, and write it down as a strategy.
Written for teachers by Peabody Teach. No ads, no affiliate links. Something wrong or missing? Tell us.