Use partitioning and known facts to multiply 2-digit by 1-digit numbers mentally

The ArithmeKit, designed for enhancing mental arithmetic skills, provides a structured approach for children to multiply 2-digit numbers by 1-digit numbers using partitioning and known facts. For instance, to multiply 46 by 4, students are encouraged to partition the number 46 into tens and units—40 and 6—and then multiply each part by 4 separately before adding the results together. This method simplifies mental calculations and helps students understand the underlying mathematical concepts. The kit includes various exercises such as matching pairs, where students have to find two elements that combine to form a correct multiplication statement, and filling in missing digits to complete given multiplication problems correctly.

Moreover, the ArithmeKit encourages students to explore multiple ways to solve a problem, as seen in the task where they must use the digits 0 through 9 to make all the statements true. This not only reinforces their multiplication skills but also promotes critical thinking. Another aspect of the kit is to challenge common misconceptions, such as whether the product of a 2-digit number and a 1-digit number is always a 2-digit number. Through practical resources or arrays, students can visually grasp concepts like distributing a number before multiplication, for example, demonstrating that 42 multiplied by 5 can be broken down into (40 x 5) + (2 x 5) or further into (20 x 5) + (20 x 5) + (2 x 5), thereby solidifying their understanding of the distributive property in multiplication.