Subtraction Worksheet Generator

How to make it

1. Size the numbersSet the top number to one to five digits and the bottom number to one to four; the larger value always ends up on top, so no answer goes negative.
2. Pick a borrowing levelNone keeps each top digit at least as big as the one below, Always demands a borrow, and Mixed blends the two.
3. Print and markChoose columns or rows and up to 40 problems, then print. The key repeats the page with each difference shown in pink.

Subtracting across zeros, worked through

Ask a class of third graders for 403 − 167 and you will see the hardest move in written subtraction. The ones column needs more: 3 is less than 7. Normally you would borrow from the tens, but the tens digit is 0, so there is nothing there. The borrow has to come from the hundreds. Four hundreds become three hundreds and ten tens; one of those tens is then passed to the ones, leaving nine tens and making thirteen ones.

Now each column works. Thirteen minus seven is 6, nine minus six is 3, three minus one is 2, and the answer is 236. On paper the top number ends up with its digits crossed out and rewritten as 3, 9 and 13. Children who see 403 as 39 tens and 13 ones, rather than as a chain of rules, tend to make fewer slips.

There is no separate switch for zeros on this page. Set the top number to three or four digits with Always, and problems like 403 − 167 or 5,006 − 2,348 can turn up among the others, since every problem must need at least one borrow and zeros occur naturally in random numbers. If a child needs a run of nothing but zero cases, print a sheet and add three or four of your own in the margin.

What each setting does

Top number and Bottom number each take a digit count. One digit means 0 to 9; two or more digits always gives a number of that length. If the bottom setting would make a larger number, the two are swapped before the sheet is drawn, which is why you will never see an answer below zero. A difference of zero can happen, as in 64 − 64, and is worth discussing when it does.

Borrowing None checks every column, so each top digit is equal to or bigger than the digit under it. Always means at least one column needs a borrow; it may be one or several. Mixed lets the generator pick freely. Layout puts problems in vertical stacks for the written method or in a line such as 82 − 9 = for mental methods like counting back or counting up. The sheet opens with 20 problems and goes up to 40.

Rows are worth using on purpose with older children too. A problem such as 61 − 58 written on one line is far quicker by counting up three than by borrowing, and 300 − 99 is easier as 300 − 100 + 1. Ask a child to say which way they chose before they write anything; deciding when not to use the column method is part of being fluent.

Borrowing, regrouping, exchanging: one idea, many names

American teachers say borrowing or regrouping, many UK schools call the method column subtraction or decomposition and talk about exchanging a ten for ten ones, and Australian classrooms use both trading and regrouping. Some parents learned a different method entirely, called equal addition, where ten is added to both the top and bottom numbers. All of these reach the same difference.

Because the answer key prints only the final difference, it works with whatever method a school uses. That matters at home: if a child is being taught decomposition, a parent showing equal addition can cause confusion. Ask what the class does, use the same words, and let the key settle whether the answer is right.

Choosing the right sheet for each grade

First grade, or Year 2 in England and Year 1 in Australia: single-digit problems in rows, where US and Canadian sheets (those that open on Letter) show CCSS 1.OA.C.6 in the footer. For teen-number facts such as 15 − 8, the mixed facts generator on the main math page with numbers up to 20 is the better fit, since this page's two-digit setting always means 10 to 99.

Second grade: two digits minus one or two digits, None first and then Mixed, matching CCSS 2.NBT.B.5. Third grade: three digits with Always, which brings in zeros, under CCSS 3.NBT.A.2. Fourth grade and up: four and five digits, the standard algorithm of CCSS 4.NBT.B.4. In England, formal column subtraction usually begins in Year 3 and extends to four digits in Year 4; in Australia written subtraction with trading typically develops across Years 3 and 4.

Children within one room differ, so it is normal to run two settings side by side: most of a class on Mixed two-digit sheets, a small group still on None, and a few early finishers on three digits.

Where children go wrong, and using the key to find out why

The most common mistake is subtracting the smaller digit from the larger in every column, regardless of which is on top. For 52 − 27, a child does 7 − 2 in the ones and writes 35 instead of 25. Next is borrowing but forgetting to reduce the digit lent: 52 − 27 becomes 35 again, by a different route. Across zeros, the typical slip is leaving the tens as 10 instead of 9.

Compare the child's answer to the pink key one column at a time. Both habits leave the tens one too high, so look at the ones digit: if it is wrong too, the child took the smaller digit from the larger (52 − 29 written as 37); if only the tens are off, the borrow was made but not recorded (52 − 29 written as 33). Teach the check too: the answer plus the bottom number should give the top number, so a sheet of matching addition sums doubles as self-checking. A number line worksheet helps children who need to see subtraction as distance, and expanded form practice helps when 403 does not yet mean 4 hundreds, 0 tens and 3 ones.

How long a sheet should be

A starter at the beginning of a lesson needs five to eight problems on a level the class has mastered, so it settles everyone rather than sorting them. For practice after a lesson on borrowing, 12 to 20 problems with Always on. For an end-of-unit check, Mixed with 24 to 30 problems tells you whether children recognize when to borrow, which is the real skill. Five-digit problems with zeros are slow, so a dozen is a full page of work.

Print one sheet per table group with New variant and nobody can copy a neighbor. For anyone who missed the lesson, Copy link brings that page back later, or type the footer's Sheet number into More options before printing.

Common Core State Standards: © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.