Math · Pre-K – Grade 5

Patterns and Algebra

Rules, unknowns, equations, and repeated structures in numbers.

HomeLearnPatterns and Algebra

Patterns and algebra teach a child to say what stays the same and what changes, in words, long before any letters appear. The strand runs from red-blue-red-blue in kindergarten to writing a rule for a number table in fourth grade, and its real content is the equal sign: the idea that two sides name the same amount.

The rule, not the next number

Ask a child what comes next in 4, 7, 10, 13 and most will answer sixteen correctly and learn nothing at all. The mathematics is in the sentence you add three each time, because a rule can be run forward, run backward, and started from anywhere. A child who only produces the next term is guessing one step ahead of you.

So change what you ask for. Ask for the rule in words before the number. Ask what the tenth term would be without writing out the ones in between. Ask them to break the pattern on purpose and see whether you can catch it. Each of those forces the rule into the open where it can actually be checked.

The equal sign is the misreading that costs the most later

Try this before reading further. Write 8 + 4 = __ + 5 in front of a child who has done a year of arithmetic pages and watch what goes in the blank. If it is twelve, they have read the equal sign as an instruction meaning write the answer here, which is exactly what a page of 8 + 4 = __ teaches. Every equation in algebra depends on it meaning something else: both sides name the same amount.

The cure is true-or-false sentences, said aloud, thirty seconds a day. Is 7 = 7 true. Is 5 + 3 = 8 true. Is 9 = 4 + 5 true. Is 6 + 2 = 3 + 5 true. Children object loudly to the backward ones at first, and the objection is the lesson. Keep going until the objection stops coming.

Eight minutes with cups, counters and a balance

This strand needs very little time and benefits from being short and frequent. Use counters your child can move, a plastic cup to hide an unknown underneath, and a balance scale if you own one, because balance is the physical picture the equal sign has been trying to convey all along.

  1. Lay out a repeating pattern with buttons or silverware and ask for the rule in a full sentence before anything else.
  2. Remove an item from the middle of the pattern rather than the end, and ask what is missing. The middle forces the rule; the end can be guessed.
  3. Put seven counters out, cover some with a cup, and say: there were seven, now I can see four, how many are hidden?
  4. Write that same situation as 4 + __ = 7, then again as 7 = 4 + __, and read both out loud.
  5. Finish with three true-or-false sentences, at least one of them written backward.

You will hear the rule before you hear the answer

When this is working, the rule arrives first: add three each time, double it, add one. Your child solves 8 + __ = 13 by counting up from eight rather than staring at the page. They accept 9 = 4 + 5 without complaint. And they invent patterns for you to solve, which is the clearest sign the structure has become theirs rather than yours.

When it is not working, the next term appears with no explanation behind it, a missing addend is answered by adding the two visible numbers, an equation with the answer on the left provokes a protest, and the letter in 3 + n = 7 is treated as a label for something rather than a number that has a value.

When the cup has to come back out

Go back to objects your child can pick up. Build the pattern physically, say the rule out loud, then break it and ask for the missing piece from the middle. For missing addends, return to the cup and counters until your child stops adding the two numbers they can see and starts counting up to the total instead.

Repeating patterns belong in pre-K and kindergarten, true-or-false equations and missing addends across first and second grade, rules and input-output tables in third and fourth, letters standing for numbers in fifth. The equal-sign misreading takes several weeks of daily true-or-false sentences to dislodge, and it tends to come back after a long stretch of one-sided computation, so keep the thirty seconds going.

First, your child should already…

This skill builds directly on:

What your child is learning

Patterns and algebra help children describe what stays the same and what changes. This begins with repeating patterns and grows into equations and variables.

Signs your child is ready

  • Can continue a simple pattern
  • Can explain a rule in words
  • Understands equality as balance

The common stumbling point

Looking only at the next number instead of naming the rule that generates the pattern.

Practice this skill

Worksheets and decodable practice for Patterns and Algebra are in the library.

Every set opens its first three worksheets to everyone; the rest are included with All Access.

Browse the whole practice library

How to know it’s mastered

The child completes, describes, or writes rules and equations for grade-level patterns.

Common questions

Why does my child answer 12 for 8 + 4 = __ + 5?
Because a year of worksheets shaped like 8 + 4 = __ taught the equal sign to mean the answer goes here, which is a reasonable reading of the evidence they were given. Fix it with short daily true-or-false sentences that put the equal sign in unfamiliar positions, and with a balance scale if you have one. Expect several weeks, and expect the old habit to resurface after a long stretch of ordinary computation practice.
Isn't algebra a middle school subject?
The symbols are. The thinking is not. Describing a rule, finding a missing number, understanding that two sides balance, and reading an input-output table are all elementary work, and they are what makes middle school algebra feel like notation rather than a new subject. A first grader who solves 4 + __ = 7 by counting up is doing algebra, whether or not anyone uses the word.
How do I teach missing addends?
Hide them physically first. Put out the total in counters, cover some with a cup, and ask how many are underneath. Then write the same situation as an equation and read it aloud together. Teach counting up from the number you can see rather than subtracting, because counting up matches what your child just did with their hands. Only once that is automatic is it worth naming the connection to subtraction.
What patterns should a kindergartner be doing?
Repeating patterns built from real objects: two elements first, spoon fork spoon fork, then three elements, then a pattern with an AAB core. Ask for the rule in words, ask what is missing from the middle, and have them build one for you to solve. Growing patterns come next, one block then two then three. Color and sound patterns count, and none of it needs a printed page.

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