2-by-2 and 2-by-3-digit multiplication problems
I go through two examples:
how to do a 2-by-2 digit multiplication, and
how to do a 3-by-2 digit multiplication.
In both cases, we need to write a ZERO in the second line of the solution. Why? Because in reality, we're multiplying by a multiple of ten, such as by 30 or by 50. Any number multiplied by 20, 30, 40, etc. will end in a zero.
The 2-by-2 digit multiplication is review from 4th grade, and the 2-by-3 or 3-by-2 one is new for 5th grade.
The next part of the lesson (a word problem by Mathy) is here:
• A multiplication word problem (discount) -...
This lesson is part of the Math Mammoth Grade 5 Curriculum. Learn more:
https://www.mathmammoth.com/complete/...
Free online practice of multi-digit multiplication (interactive):
https://www.mathmammoth.com/practice/...
Free 5th grade math videos:
https://www.mathmammoth.com/videos/gr...