665.7K
PRBEST mental maths trick for kids 🧠✨
👉 Halve one number.
Double the other.
The answer stays exactly the same.
It turns hard multiplications into easy ones.
Example 1
16 × 50
Half 16 → 8
Double 50 → 100
👉 8 × 100 = 800
Example 2
18 × 25
Half 18 → 9
Double 25 → 50
👉 9 × 50 = 450
Example 3
24 × 20
Half 20 → 10
Double 24 → 48
👉 48 × 10 = 480
Example 4
6 × 40
Half 6 → 3
Double 40 → 80
👉 3 × 80 = 240
Example 5
14 × 25
Half 14 → 7
Double 25 → 50
👉 7 × 50 = 350
Example 6
8 × 75
Half 8 → 4
Double 75 → 150
👉 4 × 150 = 600
Example 7 (keep going!)
32 × 25
→ 64 × 12.5 ❌ (not helpful)
So instead:
Half 32 → 16
Double 25 → 50
👉 16 × 50 = 800
💡 Tip for kids:
Look for numbers that can turn into 10, 50 or 100 — maths gets easier fast.
@primaryschoolonline.ie
