Quadratic equation
ax² + bx + c = 0Fill in the boxes to see the answer and the working.
Percentage of a number
result = p% × NFill in the boxes to see the answer and the working.
Percentage change
(new − old) / old × 100Fill in the boxes to see the answer and the working.
Profit or loss
(SP − CP) / CP × 100Fill in the boxes to see the answer and the working.
Simple & compound interest
SI = PRT/100 ; A = P(1 + R/100)ᵀFill in the boxes to see the answer and the working.
HCF and LCM
HCF × LCM = a × bFill in the boxes to see the answer and the working.
Triangle — cosine rule
a² = b² + c² − 2bc cos AFill in the boxes to see the answer and the working.
Triangle — sine rule
a / sin A = b / sin BFill in the boxes to see the answer and the working.
Circle area & circumference
A = πr² ; C = 2πrFill in the boxes to see the answer and the working.
Cylinder volume & surface
V = πr²h ; SA = 2πr(r + h)Fill in the boxes to see the answer and the working.
Sphere volume & surface
V = 4/3 πr³ ; SA = 4πr²Fill in the boxes to see the answer and the working.
Permutations & combinations
ⁿPᵣ and ⁿCᵣFill in the boxes to see the answer and the working.
Mean, median, mode & spread
Σx / nType a few numbers separated by commas.