In Year 4 math, students are expected to be able to multiply a 2-digit number by a 1-digit number using the standard algorithm. The standard algorithm for multiplication is a step-by-step process that involves:
Multiplying the ones digit of the 2-digit number by the 1-digit number.
Multiplying the tens digit of the 2-digit number by the 1-digit number. Multiply this with 10 , as this is at tens place.
Adding the two products from step 1 and 2.
Here is an example of the standard algorithm for multiplying a 2-digit number (25) by a 1-digit number (4):
Multiply the ones digit (5) by the 1-digit number (4) to get 20.
Multiply the tens digit (2) by the 1-digit number (4) to get 8. Multiply this by 10 to get 80
Add the products from step 1 and 2 together to get the final answer: 20 + 80 = 100.
So, 25 x 4 = 100
It’s important to note that it is also important for students to understand the concept behind the algorithm, and to be able to use other methods to check their work and improve their understanding of the concept.