Grade 1 Subtraction Mixed Review
Grade 1 subtraction mixed review sheet: 24 problems on subtraction within 20, unknown-addend facts, subtracting multiples of ten, two-digit minus one-digit without regrouping.
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Three different problem sets — same skill, same layout, fresh numbers.
Preview — Set A
Solve each problem. Read carefully — the problems change shape as you go.
- 1.5 + ___ = 6
- 2.80 - 20 =
- 3.32 - 1 =
- 4.4 - 2 =
- 5.10 + ___ = 18
- 6.40 - 20 =
- 7.96 - 2 =
- 8.16 - 10 =
- 9.1 + ___ = 18
- 10.60 - 40 =
- 11.71 - 1 =
- 12.3 - 2 =
- 13.3 + ___ = 8
- 14.20 - 10 =
- 15.20 - 1 =
- 16.12 - 4 =
- 17.10 + ___ = 12
- 18.80 - 40 =
- 19.27 - 1 =
- 20.9 - 5 =
- 21.5 + ___ = 11
- 22.30 - 20 =
- 23.78 - 6 =
- 24.3 - 1 =
What this worksheet covers
24 subtraction problems fill this mixed review page; problem 9 asks "1 + ___ = 18", and the sheet stays at that level throughout. Two of the eighteen column problems need regrouping and the rest do not, so the two cases are mixed rather than blocked and the numbers run as high as 96. Further down, problem 17 asks "10 + ___ = 12". Common Core 1.OA.6 is the slot this page fills.
Skills practised
At grade 1, subtraction is about facts within 20, unknown-addend equations, and subtracting multiples of ten, and this sheet takes one slice of that. What a student is asked to do here is subtraction within 20, unknown-addend facts, and subtracting multiples of ten. To finish it, a student has to regroup past ten rather than counting up one at a time and reason backwards from a result to a missing part. Seventeen different answers appear across the 24 problems, so a student cannot copy one result down the page.
About the mixed review format
The 24 problems are deliberately assorted — problem 9, "1 + ___ = 18" is followed by something of another shape — so the student has to read each one rather than run the last method again. Mixing regrouping and non-regrouping problems stops a student from borrowing on every problem out of habit.
Set A, Set B and Set C
The three sets come from the same generator with three different seeds: same skill, same layout, fresh numbers, and an answer key computed with the problems. Where Set A's problem 13 is "3 + ___ = 8", Set B's is "46 - 6".
How to use this worksheet
Five focused minutes beats twenty distracted ones at grade 1. Fold this mixed review in half, do one part of the 24 problems today and the rest tomorrow, and let the student use fingers or counters if they want them. Mark the 24 problems the same day using the key — an error caught immediately is a correction, and one caught next week is a habit.
One mistake to watch for
A missing-number problem like ___ − 6 = 13 is answered 7. Watch problem 17 of this mixed review — "10 + ___ = 12" — for this one.
The student subtracts the two visible numbers regardless of where the blank sits.
Ask what the whole is and what the part is before computing; drawing a part-part-whole bar makes the position of the unknown visible.
Other grade 1 subtraction formats
The same skill in the other formats available at this grade.
- Drill — Subtracting Multiples of 10 — Grade 1 Practice, 22 problems
- Timed Drill — Grade 1 Subtraction Timed Drill, 60 problems
- Missing Number — Grade 1 Subtraction Missing Number, 24 problems
- Word Problems — Grade 1 Addition and Subtraction Word Problems, 12 problems
- Vertical Format — Grade 1 Subtraction Vertical Format, 20 problems
A step either side
The same format one grade down and one grade up — the easier sheet is often the faster fix when this one is not landing.
- Kindergarten Subtraction Mixed Review — kindergarten, 20 problems
- 2.MD.6 — Subtraction on a Number Line — grade 2, 20 problems
Mixed Review sheets in other grade 1 topics
Six PDFs, no sign-up: three versions of this grade 1 subtraction mixed review and three answer keys, each 24 problems long.