Sure! Let’s solve this step by step using simple m
发表于 ： 2025年 10月 18日 05:05
鸡兔一共80只，兔脚比鸡脚多50只，问：兔多少只，鸡多少只。因为是小学题目，不可以用方程来解答，要用小学数学的观点解答
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Sure! Let’s solve this step by step using simple math — no equations, just logic and counting, like a smart 4th grader would do
We know:
- There are 80 animals total: chickens and rabbits.
- Rabbits have 4 legs. Chickens have 2 legs.
- Rabbit legs are 50 more than chicken legs.
Let’s pretend all 80 animals are chickens first.
→ Then total legs = 80 × 2 = 160 legs.
But in reality, rabbit legs are 50 more than chicken legs.
That means: if we let C = chicken legs, R = rabbit legs,
then R = C + 50.
Also, total legs = C + R = C + (C + 50) = 2C + 50.
So total legs must be 2C + 50.
But earlier, if all were chickens, we’d have 160 legs.
In real life, some chickens are actually rabbits — and each time we change one chicken into a rabbit, we add 2 extra legs (because 4 – 2 = 2).
Let’s say we changed X chickens into rabbits.
Then:
- Chicken count = 80 – X
- Rabbit count = X
- Chicken legs = (80 – X) × 2
- Rabbit legs = X × 4
- Difference: Rabbit legs – Chicken legs = 50
Now let’s think without equations:
Start with all 80 as chickens → 160 legs.
Each time we turn 1 chicken into 1 rabbit:
→ We lose 2 chicken legs, gain 4 rabbit legs → net +2 legs overall.
And we also increase the “rabbit leg advantage” by 6? Wait — let’s think differently.
Actually, every time you swap 1 chicken for 1 rabbit:
→ Chicken legs go down by 2.
→ Rabbit legs go up by 4.
→ So the difference (rabbit legs – chicken legs) increases by 6!
Why? Because before swap: suppose chicken legs = A, rabbit legs = B → diff = B – A.
After swapping 1 chicken to rabbit:
→ Chicken legs = A – 2
→ Rabbit legs = B + 4
→ New diff = (B + 4) – (A – 2) = B – A + 6 → increased by 6!
At start (all chickens): rabbit legs = 0, chicken legs = 160 → diff = -160.
We want diff = +50.
So we need to increase the difference by 50 – (-160) = 210.
Each swap increases diff by 6.
So number of swaps = 210 ÷ 6 = 35.
That means 35 chickens became rabbits.
So:
→ Rabbits = 35
→ Chickens = 80 – 35 = 45
Check:
Chicken legs = 45 × 2 = 90
Rabbit legs = 35 × 4 = 140
Difference = 140 – 90 = 50
Answer: **Rabbits = 35, Chickens = 45**
(And yes, this is how a clever kid might reason it out — with swaps and differences!)
——————————————————————————————————————————————
Sure! Let’s solve this step by step using simple math — no equations, just logic and counting, like a smart 4th grader would do
We know:
- There are 80 animals total: chickens and rabbits.
- Rabbits have 4 legs. Chickens have 2 legs.
- Rabbit legs are 50 more than chicken legs.
Let’s pretend all 80 animals are chickens first.
→ Then total legs = 80 × 2 = 160 legs.
But in reality, rabbit legs are 50 more than chicken legs.
That means: if we let C = chicken legs, R = rabbit legs,
then R = C + 50.
Also, total legs = C + R = C + (C + 50) = 2C + 50.
So total legs must be 2C + 50.
But earlier, if all were chickens, we’d have 160 legs.
In real life, some chickens are actually rabbits — and each time we change one chicken into a rabbit, we add 2 extra legs (because 4 – 2 = 2).
Let’s say we changed X chickens into rabbits.
Then:
- Chicken count = 80 – X
- Rabbit count = X
- Chicken legs = (80 – X) × 2
- Rabbit legs = X × 4
- Difference: Rabbit legs – Chicken legs = 50
Now let’s think without equations:
Start with all 80 as chickens → 160 legs.
Each time we turn 1 chicken into 1 rabbit:
→ We lose 2 chicken legs, gain 4 rabbit legs → net +2 legs overall.
And we also increase the “rabbit leg advantage” by 6? Wait — let’s think differently.
Actually, every time you swap 1 chicken for 1 rabbit:
→ Chicken legs go down by 2.
→ Rabbit legs go up by 4.
→ So the difference (rabbit legs – chicken legs) increases by 6!
Why? Because before swap: suppose chicken legs = A, rabbit legs = B → diff = B – A.
After swapping 1 chicken to rabbit:
→ Chicken legs = A – 2
→ Rabbit legs = B + 4
→ New diff = (B + 4) – (A – 2) = B – A + 6 → increased by 6!
At start (all chickens): rabbit legs = 0, chicken legs = 160 → diff = -160.
We want diff = +50.
So we need to increase the difference by 50 – (-160) = 210.
Each swap increases diff by 6.
So number of swaps = 210 ÷ 6 = 35.
That means 35 chickens became rabbits.
So:
→ Rabbits = 35
→ Chickens = 80 – 35 = 45
Check:Chicken legs = 45 × 2 = 90
Rabbit legs = 35 × 4 = 140
Difference = 140 – 90 = 50
Answer: **Rabbits = 35, Chickens = 45**
(And yes, this is how a clever kid might reason it out — with swaps and differences!)
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