Question

Silas wants to multiply $5$ with $23$ using the rods and blocks method, where rods represent tens and blocks represent ones. Which of the following statements is incorrect?

• A. We will have $10$ rods and $15$ blocks in total.
• B. We will have $11$ rods and $5$ blocks after regrouping.
• C. We will have $1$ rod and $25$ blocks after regrouping.
  
• D. We can split $23$ into $2$ tens and $3$ ones.
  

Answer 1

The correct option is C We will have $1$ rod and $25$ blocks after regrouping.


Let’s multiply $5$ with $23$ using the rods and blocks method. $5\times 23$
Let’s represent $23$ as rods and blocks. $23=2$ tens and $3$ ones
Rods represent tens and blocks represent ones.
There will be $2$ rods and $3$ blocks.
We have $5$ such groups. Therefore, there will be a total of $10$ rods and $15$ blocks.
After regrouping, there will be $11$ rods and $5$ blocks.


Therefore the statement, “We will have $1$ rod and $25$ blocks after regrouping” is incorrect.