Mental Math Subtraction

Front

What is mental math subtraction?

Back

Mental math subtraction refers to the ability to perform subtraction calculations in one's head without the use of paper, pencil, or a calculator.

Tags

CCSS.1.OA.A.1

Front

How do you round a number to the nearest ten?

Back

To round a number to the nearest ten, look at the digit in the ones place. If it is 5 or greater, round up; if it is less than 5, round down.

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

Front

What is the result of rounding 57 to the nearest ten?

Back

60

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

Front

What is the first step in subtracting 71 - 58 using mental math?

Back

Add 2 to 58 to make it easier to subtract, resulting in 60.

Tags

CCSS.2.NBT.B.5

Front

What is the result of 73 - 56 when rounding to the nearest ten?

Back

The number to round is 56, which rounds to 60, making the calculation easier.

Front

What do you add to 57 to make it a ten?

Back

You add 3 to 57 to make it 60.

Tags

CCSS.1.NBT.C.5

Front

What is the nearest ten to 82?

Back

80

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

Front

Why is rounding useful in mental math?

Back

Rounding simplifies calculations, making it easier to perform mental arithmetic quickly.

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CCSS.5.NBT.A.4

Front

What is the difference between exact subtraction and mental math subtraction?

Back

Exact subtraction gives the precise answer, while mental math subtraction often involves estimation or rounding for quicker calculations.

Tags

CCSS.2.NBT.B.5

Front

How can you check your mental math subtraction?

Back

You can check your mental math subtraction by performing the operation again or using a calculator for verification.

Tags

CCSS.1.OA.A.1