Transcript Everyday Mathematics Lattice Multiplication Lattice Multiplication Lattice multiplication involves: • Using basic facts knowledge; • Organizing a multiplication problem using a grid based on place value; •

Everyday
Mathematics
Lattice Multiplication
Lattice Multiplication
Lattice multiplication involves:
• Using basic facts knowledge;
• Organizing a multiplication problem using a grid
based on place value;
• Using the distributive property; and
• Following several well-defined steps to find the
product.
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
Since 48 × 36 is a two-digit number
times a two-digit number, we first
draw a 2 × 2 lattice box.
We carefully draw diagonals from
the top right corner to the bottom
left corner, drawing the diagonals
one box at a time.
4
8
3
6
We write one factor (48) across the
top. And we write the other factor
(36) down the right side.
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
We multiply each digit across the top by
each digit down the side, in whatever order
we choose.
Let’s start with 8 × 3.
8 × 3 = 24
4
8
2
4
3
6
We find the box where the 8 column and the
3 row intersect.
Now we record 24 as shown.
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
4 × 3 = 12
We find the box where the 4
column and the 3 row intersect.
We record the 12 as shown.
4
1
8
2
2
4
3
6
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
4
8 × 6 = 48
2
1
We find the box where the 8
column and the 6 row intersect.
We record the 48 as shown.
8
2
4
4
8
3
6
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
4
8
4 × 6 = 24
1
We find the box where the 4
column and the 6 row intersect.
We record the 24 as shown.
2
2
2
4
4
4
8
3
6
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
The diagonals separate the
digits by place-value columns.
The next step is to add along
the diagonals.
We start with the ones. There
are 8 ones.
We record 8 ones.
4
1
8
2
2
2
4
3
4
4
8
6
8
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
We add the tens.
4 tens + 4 tens + 4 tens = 12 tens
We need to regroup.
12 tens = 10 tens + 2 tens
We record 2 tens and “carry”
1 hundred (10 tens) to the
hundreds diagonal.
4
8
1
1
2
2
2
4
4
4
2
3
8
6
8
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
4
8
We add the hundreds.
2 hundreds
2 hundreds
2 hundreds
+ 1 hundred
7 hundreds
We record 7 hundreds.
1
1
2
2
2
7
4
4
4
2
3
8
6
8
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
4
8
We add the thousands.
1
1
2
2
There is 1 thousand.
We record 1 thousand.
2
7
4
4
4
2
3
8
6
8
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
The digits in the answer
are 1, 7, 2, and 8.
4
1
2
2
Each digit has a specific place
value.
1 thousand
7 hundreds
2 tens
8 ones
1
8
2
7
4
4
4
2
3
8
6
8
Everyday Mathematic
Lattice Multiplication
Solve: 48 × 36
The final answer is 1,728, because 1 thousand + 7 hundreds + 2
tens + 8 ones = 1,728.
The product of 48 × 36 is 1,728.
Everyday Mathematic
Lattice Multiplication
Children often find lattice multiplication easier to use than
other methods. It is actually simple. And the lattice helps
children organize their work.
If children know their multiplication facts and can add singledigit numbers, they can use lattice multiplication successfully.
Everyday Mathematic