Same Math › Grades 4–5 › Lattice multiplication
How does lattice multiplication work?
Lattice multiplication puts the digits of each number around a grid. Kids multiply one pair of digits per box, split each answer across a diagonal, then add along the diagonals to get the product.
- One box per pair of digits: tens above the diagonal, ones below.
- Add along each diagonal, starting at the bottom right. Carry into the next diagonal.
- Read down the left and along the bottom: 23 × 14 = 322
Why schools teach it
It separates multiplying from carrying
Lattice isn't named in the Common Core standards, but many classes still teach it, especially as an extra method. Its appeal is that kids do every single-digit fact first and save all the carrying for one adding step.
The diagonals line up the place values automatically: ones, tens, hundreds. The trade-off is that the place value is hidden, so many teachers pair it with the area model to show why it works.
At the kitchen table
What to say, and what to skip
Say this
Which two digits go with this box?
Which part goes above the line?
The tens digit. Write 0 if there isn't one: 2 × 3 is 06.Start at the bottom right. What does that diagonal add up to?
Did you carry into the next diagonal?
The most common slip.
Skip this
- Skipping the zero in a one-digit product.Writing 6 instead of 06 puts digits in the wrong diagonal.
- Adding diagonals from the left.Start at the bottom right so carries flow the right way.
- Treating it as the only method.It's a good tool, but most classes also expect the area model and the standard method.
See it in action
Solving 47 × 6 with a lattice
Set up a grid: 4 and 7 on top, 6 on the right
Fill each box
4 × 6 = 24, 7 × 6 = 42Add the diagonals from the bottom right
2, then 4 + 4 = 8, then 2: 282
Check with partial products: 6 × 7 = 42, 6 × 40 = 240, total 282.
Free practice sheet
Make a lattice multiplication sheet
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Parents also ask
Is lattice part of Common Core?
No, it isn't named in the standards. Some curricula include it, and some teachers use it as an extra strategy.
Why does it work?
Each diagonal collects one place value: ones, tens, hundreds. It's the same partial products, arranged differently.
Where does lattice come from?
It's centuries old, used in Europe and the Middle East long before the stacked method we learned.
Does it work with decimals?
Yes, by placing the decimal point along the diagonals, though most classes stop at whole numbers.