Odejmowanie możemy wykonywać "po kawałku".

Wykonajmy obliczenia.

a)

$17-5=12$  

---

$48-36=12\left[48-30=18,18-6=12\right]$  

---

$97-73=24\left[97-70=27,27-3=24\right]$  

---

---

b)
$165-32=133\left[165-30=135,135-2=133\right]$  

---

$387-76=311\left[387-70=317,317-6=311\right]$  

---

$879-65=814\left[879-60=819,819-5=814\right]$  

---

---

c)
$100-25=75\left[100-20=80,80-5=75\right]$  

---

$150-55=95\left[150-50=100,100-5=95\right]$  

---

$200-125=75\left[200-100=100,100-25=75\right]$  

---

---

d)
$100-36=64\left[100-30=70,70-6=64\right]$  

---

$200-71=129\left[200-70=130,130-1=129\right]$  

---

$350-51=299\left[350-50=300,300-1=299\right]$