Numbio Blog
How-to
How Do You Divide in Your Head?
Turn it into a multiplication question and divide in chunks, largest first. Simplify before you start, handle remainders, and check by multiplying back.
How-to
How Do You Multiply 2-Digit Numbers Mentally?
Split one number into tens and ones, multiply from the left, and keep a running total. The method, when to round instead, and how to check your answer.
How-to
How Do You Calculate Percentages in Your Head?
Find 10% by moving the decimal point, then halve, double, and add. Plus the flip trick, discounts, and why "50% more" fools shoppers.
Research
Does One Minute a Day Improve Mental Math?
Yes, for recall speed. Short daily timed practice builds arithmetic fluency better than long occasional sessions. It won't teach you new methods.
How-to
How Do You Teach a Child Mental Math?
Teach number sense before speed, keep sessions short, and watch how you help if math makes you anxious. What the research actually supports.
Research
How Do You Get Over Math Anxiety?
Math anxiety eats the working memory you need to calculate. Here is what the research shows actually reduces it, and why avoiding math makes it worse.
