About this worksheet

Doubling and halving are some of the most powerful mental maths strategies a student can learn — they turn awkward multiplications like ×4 or ×8 into a quick chain of doublings, and make ×5 as easy as finding half of ×10. Building fluency with these strategies frees up working memory for harder problems later on.

This worksheet follows EduLift’s standard four-part structure. The 16 fluency questions give students repeated practice doubling, halving, and combining these strategies to multiply by 4, 5 and 8 without using the written method. The 6 core questions apply the strategies to real-world contexts such as fundraising, bakery orders and stadium seating, including two-part problems that combine doubling or halving with a further calculation. The 4 reasoning questions ask students to explain why doubling twice is the same as multiplying by 4, and to evaluate whether halving is really the same as dividing by 2. Finally, the 3 challenge questions extend the skill with reverse puzzles that work backwards from a doubled or halved result to find the original number.

Every question and worked solution has been hand-checked for accuracy, and a full worked answer key is provided as a separate download, with clear marking guidance for the multi-step and reasoning questions.

This worksheet is aligned to the WA Curriculum code WA4MNAMU1 and is free to download for personal and classroom use.

Common errors we see in tutoring

• Doubling or halving only part of a number instead of the whole value
• Losing track of how many times a number has been doubled
• Arithmetic slips when halving an odd or large number
• Confusing 'double' with 'add 2' or 'half' with 'subtract 2'