What does the missing-number format practise?

Writing a problem as a + □ = c or □ − b = c asks a child to work backwards rather than just compute left to right. That is the first step towards algebra, and it is why the blank moves position from problem to problem.

Which number limit should I choose?

Within 10 and within 20 suit grade 1, within 100 suits grade 2, and within 1000 suits grade 3. If a child is counting on fingers rather than recalling, drop back one limit rather than adding more problems.

It hides exactly one problem per column whose answer is 67, turning the sheet into a small treasure hunt. It is a way to keep a child scanning their own answers, which is a form of checking.

Add & Subtract Worksheets

Addition & subtraction drills · Grades 1–3

Randomized addition and subtraction problems within 10, 20, 100 or 1000, with the blank placed at a random position (a + □ = c, □ − b = c, a − b = □). Choose inline or stacked layout and 2 to 4 columns; the “67 mode” hides exactly one problem per column whose answer is 67 for a small treasure hunt.

Skills: addition, subtraction, missing addend, mental arithmetic. Format: printable, randomized on every load.

Sheets are randomized, free to print, and carry no answer key on purpose – why Super Awesome Math works this way.

How to do it

When the blank is not at the end – a + □ = c rather than a + b = □ – the problem has to be worked backwards, and that is the whole point of the format.

Find where the blank is. If it comes after the equals sign, the problem is a straight calculation; if it comes before, it has to be undone.
For a + □ = c, subtract: the missing number is c − a. In 8 + □ = 14, that is 14 − 8 = 6.
For □ − b = c, add: the missing number is c + b. In □ − 4 = 12, that is 12 + 4 = 16, because the start had to be bigger than what was left.
Put the answer back into the original problem and read it through. 8 + 6 = 14 is true, so 6 is right.

Where it goes wrong

Applying the operation shown instead of its inverse. Seeing a plus sign and adding everything in sight gives 22 for 8 + □ = 14.
Subtracting the wrong way round in □ − b = c. The unknown here is the largest of the three numbers, not the smallest.

Frequently asked questions

What does the missing-number format practise?: Writing a problem as a + □ = c or □ − b = c asks a child to work backwards rather than just compute left to right. That is the first step towards algebra, and it is why the blank moves position from problem to problem.
Which number limit should I choose?: Within 10 and within 20 suit grade 1, within 100 suits grade 2, and within 1000 suits grade 3. If a child is counting on fingers rather than recalling, drop back one limit rather than adding more problems.
What is 67 mode?: It hides exactly one problem per column whose answer is 67, turning the sheet into a small treasure hunt. It is a way to keep a child scanning their own answers, which is a form of checking.

Settings

Operation: addition, subtraction or both
Limit: within 10, 20, 100 or 1000
Layout: inline or stacked (vertical)
Columns: 2, 3 or 4 (20–40 problems)
67 mode: one hidden answer of 67 per column

Example problems

8 + 5 = □
□ + 6 = 14
17 − 9 = □
□ − 4 = 12

More Arithmetic

Kindergarten Math – Counting, first sums and skip counting
Multiplication – Times tables & grid practice
Column Multiplication – Long multiplication practice
Division – Division facts, with or without remainders
Long Division – Long division practice
Multiplication & Division Tables – Every times table as a column of facts