We're humming as we complete seven years...

There are 7 letters in HeyMath!
And Sapta Swaras means 7 octats
All opposite side numbers on a dice add up to 7
Buddha's 7 steps at birth took him to heaven
Pythagoreans called it the perfect number, 3 and 4
And rainbows have violet, indigo, blue, green, yellow, orange and red
So, 7 is an interesting number by all accounts!

HeyMath! turned 7 on 07.14.07