Latihan tambahan

加数未知 = tambahan yang tidak diketahui 全部化成毫升。T 是加上去的，减三千四百也要算进去。可以先把两个已知数合起来：五千二百减三千四百；算式就变成“这个差加 T 等于结果”，T 就是结果减去这个差。最后放回去检查一次。 例子：3 ℓ + S − 2 ℓ = 1 ℓ 600 mℓ → 1 000 + S = 1 600 → S = 600。 注意：先分清楚每个已知数是被加上还是被减掉的。

an unknown amount added = tambahan yang tidak diketahui Change everything into millilitres. T is added, and 3 400 is taken away. First combine the two known amounts: 5 200 − 3 400. The sentence becomes that difference + T = result, so T is the result minus that difference. Finally test T in the number sentence. Example: 3 ℓ + S − 2 ℓ = 1 ℓ 600 mℓ → 1 000 + S = 1 600 → S = 600. Watch out: first decide whether each known amount is added or taken away.

写出算式再求 = tulis ayat matematik dahulu 把故事写成算式：原来的水，减去倒出的（未知），再加上爸爸加入的，等于现在的水。全部化成毫升后，可以倒推：现在的水先减去爸爸加入的，得到倒出以后剩下的水；再用原来的水减去它，就是倒出的量。 例子：6 ℓ − ? + 1 ℓ = 5 ℓ 300 mℓ → 5 300 − 1 000 = 4 300 → 6 000 − 4 300 = 1 700 mℓ。 注意：7 ℓ 20 mℓ 化成毫升，二十在十位和个位。

write the number sentence first = tulis ayat matematik dahulu Turn the story into a number sentence: water at first − water poured out (unknown) + water added by father = water now. In millilitres, work backwards: water now minus the water father added gives what was left after pouring; the water at first minus that is the amount poured out. Example: 6 ℓ − ? + 1 ℓ = 5 ℓ 300 mℓ → 5 300 − 1 000 = 4 300 → 6 000 − 4 300 = 1 700 mℓ. Watch out: 7 ℓ 20 mℓ in millilitres has 20 in the tens and ones places.

倒推两步 = kira ke belakang dua langkah Q 在最前面，后面先减一个容量、再加一个容量。倒推时次序和运算都要反过来：从结果开始，先把最后加上的减回去，再把中间减掉的加回去。一升九十毫升化成毫升时，九十在十位和个位。求出以后，代入原式检查。 例子：R − 500 + 1 000 = 2 700 → 2 700 − 1 000 = 1 700 → 1 700 + 500 = 2 200，R = 2 200。 注意：倒推时要从最后一步开始，不能从前面开始。

work back two steps = kira ke belakang dua langkah Q comes first, followed by taking away one volume and then adding another. To work backwards, reverse both the order and the operations: start from the result, take away what was added last, then add back what was taken away. 1 ℓ 90 mℓ in millilitres has 90 in the tens and ones. Check by putting Q back. Example: R − 500 + 1 000 = 2 700 → 2 700 − 1 000 = 1 700 → 1 700 + 500 = 2 200, R = 2 200. Watch out: work backwards from the last step, not from the front.