M3.2.2 For the adult
Short multiplication
How do I work out 4 × 326 on paper?
What this chapter teaches
The grid method shows that a number is multiplied part by part, by place value. The written column method does the same calculations in a short form, and the carry is the tens of one product added to the next.
Three questions to ask
There is no one right wording. Listen for the idea.
- How would you split 326 before multiplying it by 4?
- Where does the carried 2 come from in 4 × 326?
- Why do you multiply the digit before you add the carry?
After the chapter, the learner can
- Multiply a 3 or 4 digit number by a 1 digit number
- Use the grid method to show what each part means
What they copy into their notebook
Grid method: split into hundreds, tens and ones, multiply each part, add the boxes. In columns: start at the ones. Multiply, add the carry, write the last digit, carry the rest.