Double Digits: Mental Math

How fast can you solve 7 × 38 in your head? Double Digits is a drill for people who want to multiply two-digit numbers quickly. CONQUER EVERY NUMBER FROM 1 TO 99 The home screen is a grid of the numbers 1 to 99. Pick one and you get all 90 combinations of that number with every two-digit number, from 10 to 99. Solve them all and the number is cleared. Each cleared number keeps your best time. Filling in all 99 is the goal. WATCH YOURSELF GET FASTER Take on the same number again and your times are drawn as a line chart. The horizontal axis is your attempt number, the vertical axis is your finishing time. A line sloping downward is progress you can see. The days you practice are recorded automatically, along with your current streak. PRACTICE ANY COMBINATION Want to drill only 7 and 8, and only against the 20s? You can pick exactly which numbers to learn and what to multiply them by, so you can attack your weak spots directly. INPUT THAT KEEPS UP The keypad handles multiple fingers at once, so nothing is dropped no matter how fast you type. Correct answers give a light haptic tap and a sound, then move straight on. COMPETE GLOBALLY Leaderboards are supported through Game Center, with a separate board for every number. Signing in is optional; decline it and every practice feature still works. Light and dark appearance are both supported, following your device setting automatically.