Japanese Multiplication Method: 23 x 12

The question, solved step by step

23 x 12 = ?

US way: 23 x 2 = 46.
US way: 23 x 10 = 230.
US way: add the parts, 46 + 230 = 276.
Japan way: draw 2 lines for the 2 in 23, then 3 lines for the 3, leaving a gap.
Japan way: draw 1 line for the 1 in 12, then 2 lines for the 2, crossing the first lines.
Count the dots where lines cross in each area: 2, then 7, then 6. Read the answer: 276.

Answer

23 x 12 = 276

The common mistake

Forgetting the zero in the second partial product, so 23 x 10 becomes 23 instead of 230. Then 46 + 23 = 69, which is far too small. 23 x 12 should be a bit more than 23 x 10.

Parent tip

Have your child estimate first: 23 x 12 is close to 20 x 10 = 200, and a bit more. If the answer is not a little above 200, something went wrong.

Video transcript

0:00Twenty three times twelve. The USA way, or the Japan way?

0:05USA way: twenty three times two is forty six. Times ten is two thirty. Add them: two seventy six.

0:12Japan way: draw two lines, then three lines.

0:15Now one line, then two lines across.

0:18Count the dots: two, seven, six!

0:20Two seventy six again!

0:22Which way is easier? Comment USA or Japan!

Questions parents ask

What is the Japanese multiplication method?

It is a line method: draw one set of lines for each digit of the first number and cross them with lines for the digits of the second number. Counting the dots where the lines cross, group by group, gives the digits of the answer. For 23 x 12 you count 2, 7 and 6.

How do you multiply 23 x 12 the standard US way?

Multiply 23 x 2 = 46, then multiply 23 x 10 = 230, and add: 46 + 230 = 276. These are called partial products. Writing the zero in 230 is the step children miss most often.

What do you do when a group of dots is 10 or more in the Japanese method?

Carry it, just like in column addition. Keep the ones digit in that group and add the tens digit to the group on its left. This happens often with larger digits, so it helps to practice with small numbers like 23 x 12 first.

Which multiplication method should my child use?

The one your child understands and gets right. The standard method is what most US classrooms and tests expect, so know it well. The line method is a good visual way to check an answer or to make multiplication more fun.

Japanese multiplication method: 23 x 12