Lattice multiplication, explained for parents
Lattice multiplication puts the digits around a grid, multiplies each pair of digits into a box split by a diagonal, then adds along the diagonals. For 46 × 23 the diagonals give 1, 0, 5, 8, so the answer is 1,058. It keeps multiplying and adding apart, which some children find tidier.
Checked October 29, 2026 against the sources listed at the end.
How it works: 46 × 23
- Draw a grid with one column for each digit of 46 and one row for each digit of 23. Write 46 across the top and 23 down the right side.
- Draw a diagonal through each box from top right to bottom left.
- Multiply the digit above each box by the digit beside it, and write the answer with its tens above the diagonal and its ones below: 4 × 2 = 08, 6 × 2 = 12, 4 × 3 = 12, 6 × 3 = 18.
- Add along each diagonal strip, starting at the bottom right: strip 1 adds to 8, write 8; strip 2 adds to 5, write 5; strip 3 adds to 10, write 0, carry 1; strip 4 adds to 0 plus 1 carried, write 1.
- Read the answer from the top left, down and along the bottom: 1,058. And 46 × 23 = 1,058.
Why some schools teach it
Lattice multiplication isn't in the Common Core. The standards ask fourth graders to multiply with strategies based on place value and to explain them with equations, arrays or area models, and fifth graders to use the standard algorithm. Some programs offer the lattice as one more way to get there; many don't teach it at all.
What it does well: every box is a single-digit fact, and all the carrying happens at the end, in one place. Children who lose track of carried digits in the standard method sometimes find it calmer.
What it hides: the place value. The box for 4 × 2 really means 40 × 20 = 800, but the lattice writes it as 08. A child can get the right answer without seeing why, which is why many teachers prefer the area model for explaining and use the lattice only as a checking tool.
Helping with homework
- Write a 0 in the tens triangle when a product is a single digit (2 × 3 = 06). Leaving it blank is the most common slip.
- Draw the diagonals all the same way, top right to bottom left, or the strips won't line up.
- Add strips from the bottom right and carry into the next strip up and to the left.
- Check with an estimate: 46 × 23 is near 50 × 20 = 1,000.
- Ask the teacher whether the lattice is a method they want used on tests, or an extra to try. It varies from class to class.
Try it
The single-digit facts in each box come straight off a multiplication chart. For more problems with answer keys, print two-digit by two-digit multiplication worksheets and check the answers with the lattice.
Questions parents ask
Why is it called lattice multiplication?
Because the grid with its diagonals looks like a lattice, the crisscross wooden screen used in gardens.
Should my child use lattice or the standard method?
Whatever the teacher is asking for right now. By the end of fifth grade the Common Core expects the standard algorithm, so lattice is best treated as a stepping stone or a way to check.
Practice at your child's level
Peabody, our site for children, has free stories and learning games written at each reading level and math grade, with no sign-up. Start where your child is comfortable, not where the calendar says.
- Start reading on Peabody Peabody asks your child's grade, starts the stories a little under it, and moves the level as books run easy or hard.
- Reading levels and math by grade Where each grade starts, and a page for every level and math path.
- The free library Stories sorted by level, to read on screen.
- Decodable readers Stories built from the sounds a beginning reader has been taught.
Where this comes from
Written for parents, to use alongside your child's teacher, not instead of them. General information only, not professional, medical or legal advice. Checked on October 29, 2026. Something wrong or out of date? Write to hello@peabody.kids.