Today's Classroom Activities :

Easy Multiplication

Multiplying Cards
Math Remove the face cards from a deck and lay the remaining cards face down. Players choose two cards to multiply. When all the cards have been used, check the answers and give two points for each correct answer. The highest score wins.

Multiplication Models - Students will love these interactive activities.

"Magical" calculations (Grades 3-5)
These mental math tricks are so slick, they seem like magic.

Multiplying by 5: Divide the number by 2 and multiply by 10. For example, to multiply 18 x 5, divide 18 by 2 to get 9, then multiply 9 by 10 to get 90. Give your students a series of numbers to multiply by 5 – most will be able to do this quickly in their heads.

What about odd numbers that don't divide evenly by 2? Just think in terms of decimals. For example, 41 x 5. First take half of 41, which is 20.5, then multiply by 10 to get 205. It works every time.

Multiplying by 11: To multiply a two-digit number by 11, write the two digits with a space between them and, in that space, write the sum of the two digits. For example, to multiply 52 x 11, write 5__2. What goes in the blank? 5 +2, or 7, so the answer is 572.

Give a few more examples, and have your students check with a calculator or pencil and paper to verify their results. Make sure that the two digits when added together are 9 or less, because it's a little more complicated when they sum to 10 or greater.

Can your students explain why this works? Having them calculate with pencil and paper can help explain. Be sure to emphasize the place value concepts during your discussion.