Multiply numbers using efficient written or mental methods

The ArithmeKit 5.15 from Buzzard Publishing, part of the CanDoMaths series, provides a comprehensive approach to multiplying numbers using efficient written and mental methods. The resource challenges students to determine the most efficient method—mental calculation or written algorithm—for a variety of multiplication problems. The exercises include straightforward multiplications such as 430 x 15 and more complex ones like 37.24 x 17. Additional tasks require students to calculate products using either a written method or mental strategies with jottings, such as 46 x 99 or 87 x 1999, and then decide which method proves to be the most efficient for each calculation.

Furthermore, the kit encourages learners to create their own multiplication problems that would be best solved using mental methods, promoting a deeper understanding of number sense and arithmetic strategies. It includes an engaging activity where students must decide whether they agree with Colin, who prefers a written method, or Coco, who opts for jottings, for multiplying 234 by 25. The resource also presents missing digits challenges and problems requiring the use of all digits from 0-9 once, enhancing problem-solving skills. To solidify the concept, students are tasked with convincing Coco that an efficient method for calculating 244 x 25 is to multiply by 100 and then divide by 4, illustrating the practical application of mental methods in simplifying complex calculations.