Latihan tambahan

先加后减 = tambah dahulu, kemudian tolak 算式先加后减，从左到右算：先把前两个数加起来，写下这个中间结果；再用中间结果减去最后的数。中间结果不是最后答案。 例子：6 000 + 4 000 − 3 000 → 10 000 − 3 000 = 7 000。 注意：第一步做完就停下来是常见的错误；每一步都要检查进位和借位。

add, then subtract = tambah dahulu, kemudian tolak The sentence adds and then subtracts, so work from left to right: add the first two numbers, write down the middle answer, then subtract the last number from it. Example: 6 000 + 4 000 − 3 000: 10 000 − 3 000 = 7 000. Watch out: stopping after step 1 is a common mistake, and check the carrying and regrouping in each step.

先减后加 = tolak dahulu, kemudian tambah 从左到右：先从整万数减去中间那个数（要连续借位），写下中间结果；再加上最后的数。也可以用“两数各减 1”让第一步不用借位。 例子：10 000 − 3 000 + 500 → 7 000 + 500 = 7 500。 注意：不要先把后面两个数加起来再减；那样会把应该加的数也减掉。

subtract, then add = tolak dahulu, kemudian tambah Left to right: take the first number from the whole ten thousand (regrouping all the way), write down the middle answer, then add the last number. Taking 1 from both numbers can avoid the borrowing in step 1. Example: 10 000 − 3 000 + 500: 7 000 + 500 = 7 500. Watch out: do not add the last two numbers first, or the number to be added gets subtracted.

用掉减、存入加 = belanja tolak, simpan tambah 先把故事写成算式：原来的钱，用掉的要减，存入的要加，按故事发生的次序从左到右写。再从左到右一步一步算，答案写 RM。 例子：RM100，用掉 RM30，又存入 RM20 → 100 − 30 + 20 = RM90。 注意：存入的钱是加进去的，不能也减掉；把两笔钱都加进去也不对。

spend means minus, save means plus = belanja tolak, simpan tambah Write the story as a number sentence in the order things happen: start with the money, subtract what is spent and add what is saved. Then work from left to right and write RM in the answer. Example: RM100, spend RM30, then save RM20: 100 − 30 + 20 = RM90. Watch out: money saved is added, not subtracted, and adding both amounts is wrong too.

倒推 = kerja ke belakang 未知数在最前面，先减后加得到结果。从结果倒着走：最后一步是加，倒回去就减；前一步是减，倒回去就加。最后把答案代回原式检查。 例子：□ − 50 + 20 = 70 → 70 − 20 = 50，50 + 50 = 100；检查 100 − 50 + 20 = 70。 注意：倒推要从最后一步开始，加变减、减变加；次序弄反，答案就不对。

work backwards = kerja ke belakang The unknown is at the start; something is taken away, then something is added. Start from the result and undo the last step first: undo an addition by subtracting and a subtraction by adding. Check in the sentence. Example: □ − 50 + 20 = 70: 70 − 20 = 50, 50 + 50 = 100; check 100 − 50 + 20 = 70. Watch out: start from the last step and swap each operation; the wrong order gives the wrong answer.