This multiplication trick is so easy - but you probably don't know it...because it doesn't get taught. That's OK - youtube and tecmath has your back - with this, the easiest multiplication trick you were EVER taught in school!
Here is THE mental multiplication lesson playlist - progressing you through your mental multiplication. https://www.youtube.com/playlist?list=PLjbxBzUM6SLk4VGcPW1Jz2tZdaZ6YZEKa
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