Unit 27
Akal Pintar
Lengkapkan peta pemikiran:
? ÷ 10 = 64
? ÷ 100 = 64
? ÷ 1 000 = 64
思维图补空 = lengkapkan peta pemikiran
三道除法的商都是 64，但除数分别是 10、100、1 000，所以被除数都不一样。我们要用“除法是乘法的逆运算”来倒推：被除数 = 商 × 除数。
例子：□ ÷ 10 = 5 → □ = 50。
注意：除数越大，被除数也要越大，商才会一样。
complete the thinking map = lengkapkan peta pemikiran
All three divisions give 64, but they divide by 10, 100 and 1 000, so the starting numbers are different. Use the fact that division undoes multiplication: starting number = answer × divisor.
Example: □ ÷ 10 = 5, so □ = 50.
Watch out: the bigger the divisor, the bigger the starting number must be for the answer to stay the same.
Cara
Darab untuk mencari nombor
64 × 10 · 64 × 100 · 64 × 1 000
640 ÷ 10 = 64
6 400 ÷ 100 = 64
64 000 ÷ 1 000 = 64
6 400 ÷ 100 = 64
64 000 ÷ 1 000 = 64
用乘法倒推 = darab untuk cari
商 64 乘除数就是被除数：64 × 10 = 640，64 × 100 = 6 400，64 × 1 000 = 64 000。算好后可以代回去检查：640 ÷ 10 = 64，对了。
例子：□ ÷ 100 = 37 → □ = 3 700。
注意：乘几个 0 的数，就补几个 0。
work back with multiplication = darab untuk cari
The answer 64 times the divisor gives the starting number: 64 × 10 = 640, 64 × 100 = 6 400, 64 × 1 000 = 64 000. Check by dividing: 640 ÷ 10 = 64, which is right.
Example: □ ÷ 100 = 37, so □ = 3 700.
Watch out: add as many zeros as the divisor has.
Cuba
? ÷ 100 = 480. Apakah nombor dalam ??
倒推 = cari nombor asal
题目知道商和除数，要找被除数。除法是乘法的逆运算，所以被除数 = 商 × 除数。除数是一百，就在商的后面补两个 0。求出来以后，再把它除以一百，看是不是回到题目的商。
例子：□ ÷ 100 = 36 → □ = 36 × 100 = 3 600。
注意：补 0 的个数跟着除数走：除以十补一个，除以一百补两个。
work back = cari nombor asal
We know the answer and the divisor and must find the number that was divided. Division undoes multiplication, so that number = answer × divisor. The divisor is one hundred, so write two zeros after the answer. Then divide it by one hundred to check that you get back the answer in the question.
Example: □ ÷ 100 = 36, so □ = 36 × 100 = 3 600.
Watch out: the number of zeros follows the divisor: one for ten, two for one hundred.
Ringkasan