Grades 1–5 · printable + timed
Subtracting 9 Timed Test
Print it with the answer key on page 2, or run the timer here.
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- 1 9 − 0 9
- 2 10 − 1 9
- 3 12 − 3 9
- 4 21 − 12 9
- 5 10 − 1 9
- 6 15 − 9 6
- 7 13 − 9 4
- 8 12 − 3 9
- 9 17 − 9 8
- 10 17 − 9 8
- 11 14 − 9 5
- 12 16 − 9 7
- 13 19 − 10 9
- 14 11 − 9 2
- 15 15 − 9 6
- 16 16 − 7 9
- 17 9 − 0 9
- 18 11 − 9 2
- 19 15 − 6 9
- 20 16 − 9 7
Correct 0 Wrong 0 Blank 20
Elapsed 0s Left 60s
A timed sheet on subtracting 9
Subtracting 9, from 9 − 9 to 21 − 9. Every problem on the sheet is drawn from that set and nothing outside it.
Choose 20, 50 or 100 problems and a limit of 1, 2 or 5 minutes, then print the sheet with its answer key on page two, or start the timer and type into the same grid. The problems are drawn again every time the page loads, so a second sheet is not a copy of the first. How the counts and limits work is on its own page, along with what a timed test does and does not measure.
Thirteen rows, with the answers
| Problem | Answer |
|---|---|
| 9 − 9 | 0 |
| 10 − 9 | 1 |
| 11 − 9 | 2 |
| 12 − 9 | 3 |
| 13 − 9 | 4 |
| 14 − 9 | 5 |
| 15 − 9 | 6 |
| 16 − 9 | 7 |
| 17 − 9 | 8 |
| 18 − 9 | 9 |
| 19 − 9 | 10 |
| 20 − 9 | 11 |
| 21 − 9 | 12 |
Where subtracting 9 goes wrong
Taking 9 away is taking 10 and giving 1 back — 16 − 9 = 6 + 1 = 7. The ones digit of the answer therefore sits exactly one above the ones digit of the original number: in 16 − 9 = 7, the 7 is 6 + 1. This is effectively the only self-check available anywhere in subtraction.
Three that come up
- How do you subtract 9 in your head?
- Take away ten first, then give one back, because nine is one short of ten. 17 − 9 lands on 7, then 8.
- Is there a check for 9s subtraction?
- Yes. The ones digit of the answer is one more than the ones digit you started with — 15 − 9 = 6, and 6 is 5 + 1.
- Why is subtracting 9 easier than subtracting 7?
- Nine is one away from ten, so the correction is a single step rather than a split.
What the standards and the critics actually say
Common Core State Standards for Mathematics (PDF), page 19 — 2.OA.B.2 “By end of Grade 2, know from memory all sums of two one-digit numbers.” thecorestandards.org — CCSSI_Math Standards.pdf
NCTM — Procedural Fluency in Mathematics (position statement) “Timed tests do not assess fluency and can negatively affect students, and thus should be avoided.” nctm.org — Procedural Fluency in Mathematics
youcubed — Fluency Without Fear “For about one third of students the onset of timed testing is the beginning of math anxiety.” youcubed.org — Fluency Without Fear
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