Two facts answer almost every division item: mitosis makes two genetically identical cells with the SAME chromosome number, meiosis makes four haploid cells with HALF the number. Use the number change to label a diagram arrow and the counts to tally products.
Trigger: a life-cycle diagram with n and 2n, 'which stage is meiosis', or 'how many cells / chromosomes'.
Instances:
(i) label an arrow: number unchanged (or haploid growing to haploid) is mitosis, number halved (diploid to haploid) is meiosis, number doubled is fertilisation and not a division at all;
(ii) count products: each mitosis multiplies the cell count by two, a final meiosis multiplies by four;
(iii) sanity checks: mitosis never makes three or four cells, and gametes come from diploid stem cells through meiosis, never from haploid ones.
