Multiplication tables are often taught by rote and sometimes are difficult for students to grasp. Certain techniques, however, turn multiplication into a trick or a game that might reel in reluctant learners and encourage them to find the fun in math.
Larger Numeral Multiplication Trick
Students who struggle with multiplication might appreciate this quick trick for multiplying any two numbers between 11 and 19 in their heads. Not only is the result impressive, but performing it may encourage reluctant children to practice multiplying smaller numbers so that they can do it. Start with any two numbers between 11 and 19, for instance 12 times 15. The larger number goes on top, making the equation 15 times 12. Ask your student to add the top number to the right hand number from the bottom number. In this case 15 plus two, making 17, then add a zero, for 170. Now they multiply the two righthand numbers, five times two in this example, making 10. The last step is to add the two numbers, 170 plus 10, and they have their answer. Multiplying 15 times 12 equals 180.
Some multiplication tables have rules. These are often the easiest for students to learn. Teach them that any number times zero equals zero and any number times one equals itself. Once they know that multiplying by 10 involves adding a zero to the end of any number, they'll have three of the tables down. Elevens are easy to learn once students know that it doubles a number, so that two times 11 is 22 and three times 11 is 33, and so on. Learning these rules gives confidence to students who are learning the multiplication tables because they are easy to master.
Students can add two more multiplication tables when they know how to count by twos and fives. Once they have these ways of counting down, they'll be able to figure out the two and five times tables even up to large numbers. Now that students have mastered times tables for zero, one, two, five and 10, they'll have the tools for figuring out less formulaic multiplication tables. Teach them that the four times tables is simply twice the twos or the fives minus the number. The sevens are the fives plus the twos. Eventually students should be able to memorize the times tables to 12, but having tools for figuring out difficult answers on their own may reduce stress during that process.
Ask your students if they know that their hands are quick and efficient nine times table calculators. This trick is impressive enough that it might encourage an interest in math in even reluctant students. Have them lay their hands on their desks in front of them. Starting from the left, tuck under one finger at a time. The left pinkie reflects nine times one. There are no fingers on the left and nine on the right, making the answer nine. Now unfold the pinkie and tuck in the ring finger. One finger on the left and eight on the right represent 18, or the answer to nine times two. This works through 10, when students tuck in their right pinkie, leaving nine fingers on the left and zero on the right, or the number 90.