Latihan tambahan

奇数加奇数 = ganjil tambah ganjil 题目要两个数都是奇数，而且和是指定的数。每一组都检查：两个数的个位是不是都是单数；两个数加起来是不是等于总数。两项都对才算。 例子：11 + 49 = 60，11 和 49 都是奇数，所以符合“两个奇数、和为 60”。 注意：奇数加奇数会得到偶数；一组里只要有一个偶数就不符合。

odd plus odd = ganjil tambah ganjil Both numbers must be odd and add up to the given total. For each pair check that both ones digits are odd and that the sum is right. Example: 11 + 49 = 60, and both are odd, so this pair fits two odd numbers with a total of 60. Watch out: odd plus odd gives an even total, and one even number spoils the pair.

代入求另一个 = gantikan untuk cari yang lain 题目已经告诉我们 e 的值，要求 f。把 e 的值代进 e + f = 总数，f 就是总数减去 e。算完以后还要检查：e 是不是偶数，f 是不是奇数，两数加起来是不是总数。 例子：若 e = 12，f = 51 − 12 = 39；12 是偶数、39 是奇数、12 + 39 = 51。 注意：求 f 要用减法；把两个数加起来得到的数比总数还大，一定不对。

substitute to find the other = gantikan untuk cari yang lain The value of e is given; find f. Put e into e + f = total, so f is the total minus e. Then check that e is even, f is odd and the two add up to the total. Example: if e = 12, then f = 51 − 12 = 39; 12 is even, 39 is odd and 12 + 39 = 51. Watch out: find f by subtracting; adding gives a number bigger than the total.

用规律判断 = gunakan corak 题目问：能不能一个奇数加一个偶数等于这个总数？先回想规律：奇数 + 偶数一定是奇数；奇数 + 奇数、偶数 + 偶数都是偶数。再看总数是奇数还是偶数，就能判断可不可能，不必一个一个去试。 例子：总数 17 是奇数，可以是一奇一偶，例如 8 + 9；总数 18 是偶数，就不可能是一奇一偶。 注意：先判断总数的奇偶，再下结论。

use the pattern = gunakan corak Can one odd and one even number add up to this total? Remember: odd + even is always odd, while odd + odd and even + even are even. Check whether the total is odd or even, and you can decide without trying numbers one by one. Example: 17 is odd, so it can be one odd and one even number, such as 8 + 9; 18 is even, so it cannot. Watch out: decide whether the total is odd or even before you conclude.