Akal Pintar

倒着算 = kerja ke belakang 先把二十九周一天换成天：二十九乘七加一等于二百零四天。除以乘数六，得三十四天，这就是被乘的时间。四周是二十八天，三十四减二十八等于六，所以缺的是六天。用竖式检查：六乘六天是三十六天，换成五周一天，加上二十四周，刚好二十九周一天。 例子：2 周 □ 天 × 3 = 7 周 2 天 → 51 天 ÷ 3 = 17 天 = 2 周 3 天，所以 □ = 3。 注意：检查时要进位。

work backwards = kerja ke belakang Change 29 weeks 1 day into days: 29 × 7 + 1 = 204 days. Divide by 6: 34 days, the time being multiplied. 4 weeks are 28 days, and 34 − 28 = 6, so the missing number is 6. Check: 6 × 6 days = 36 days = 5 weeks 1 day, plus 24 weeks makes 29 weeks 1 day. Example: 2 weeks □ days × 3 = 7 weeks 2 days → 51 days ÷ 3 = 17 days = 2 weeks 3 days, so □ = 3. Watch out: regroup when checking.

补全年月乘法 = lengkapkan pendaraban tahun dan bulan 倒着算：先把等号右边的积全部换成月（年数乘十二，再加月）；再除以乘数，得到被乘的时间有多少个月；然后减去已知的年换成的月，剩下的月数就是方框里的数。最后用乘法检查一次。 例子：2 年 □ 月 × 3 = 7 年 9 个月 → 93 ÷ 3 = 31 个月 = 2 年 7 个月，□ 是 7。 注意：一年是十二个月，换算时不要乘十。

complete the years and months = lengkapkan pendaraban tahun dan bulan Work backwards: change the product into months (years × 12, plus the months), divide by the multiplier to get the months being multiplied, then take away the known years in months. The months left are the missing number. Check with multiplication. Example: 2 years □ months × 3 = 7 years 9 months → 93 ÷ 3 = 31 months = 2 years 7 months, so □ is 7. Watch out: a year is 12 months; do not multiply by 10.

求乘数 = cari pendarab 这次缺的是乘数，也就是“乘了几次”。方法：把被乘的时间和积都换成同一个小单位（天），再用积除以被乘的时间，商就是乘数。最后把乘数乘回去检查，看是不是刚好得到积。 例子：1 周 2 天 × □ = 3 周 6 天 → 9 天和 27 天 → 27 ÷ 9 = 3。 注意：两个时间都要先换成天才能相除，不能只用周数相除。

find the multiplier = cari pendarab This time the multiplier is missing: how many times the time was taken. Change both the time and the product into the same small unit (days), then divide the product by the time; the quotient is the multiplier. Multiply back to check. Example: 1 week 2 days × □ = 3 weeks 6 days → 9 days and 27 days → 27 ÷ 9 = 3. Watch out: change both times into days before dividing; do not divide the weeks only.