Mental Math

Front

What is mental math?

Back

Mental math refers to performing calculations in your head without the use of calculators or paper.

Tags

CCSS.1.OA.C.6

CCSS.2.OA.B.2

Front

How do you subtract large numbers mentally?

Back

Break down the numbers into smaller, manageable parts. For example, to subtract 3999 from 6000, think of it as 6000 - 4000 + 1.

Tags

CCSS.4.NBT.B.4

Front

What is the result of 29 ÷ 100?

Back

0.29

Tags

CCSS.4.NF.C.6

Front

How do you solve 3.81 − 2.79?

Back

Align the decimal points and subtract: 3.81 - 2.79 = 1.02.

Tags

CCSS.5.NBT.B.7

Front

What is the meaning of 'less than' in math?

Back

'Less than' indicates a subtraction operation. For example, 'ninety-nine less than two hundred and eighteen' means 218 - 99.

Tags

CCSS.1.OA.A.1

Front

How do you add time?

Back

When adding time, add the minutes first, and if they exceed 60, convert to hours. For example, 9:55 AM + 18 minutes = 10:13 AM.

Tags

CCSS.3.MD.A.1

Front

What is the difference between addition and subtraction?

Back

Addition combines numbers to find a total, while subtraction finds the difference between numbers.

Tags

CCSS.1.OA.A.1

Front

What is a decimal?

Back

A decimal is a fraction expressed in a special form, using a decimal point to separate the whole number from the fractional part.

Front

How do you round numbers?

Back

To round a number, look at the digit to the right of the rounding place. If it's 5 or more, round up; if it's less than 5, round down.

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

Front

What is the importance of estimating in mental math?

Back

Estimating helps you quickly assess the reasonableness of an answer before calculating the exact value.