Adding using the column method

Maths

Estimating before calculating helps you set out your calculations on paper.

Estimating before calculating helps you to practise your adding strategies.

Estimating before calculating provides an approximate answer which you can check your actual answer against.

Estimating before calculating shortens the amount of time it takes to solve an equation.

Why might it be useful to estimate the answer to an equation prior to calculation?

2. What is a suitable estimate for the equation: 451 082 + 339 721?

3. Use the column method to solve: 289 109 + 463 229 =

4. Use the column method to solve: 632 781 + 10 385 =

5. Use the column method to solve: 5411 + 1389 + 2013 =

Adding and subtracting using the column method.

Rounding numbers in an equation to provide an approximate answer before calculation.

Using decimal numbers in addition equations.

Using whole numbers in addition equations.

Round '456 244' to the nearest multiple of 10 000.

3. Using rounding to the nearest multiple of 10 000 to estimate the answer to: 341 782 + 456 913 =

4. Use rounding to the nearest multiple of 1000 to estimate the answer to: 187 221 + 243 891 =

Rounding to estimate always takes much longer than actually calculating the answer.

Rounding to estimate decreases the accuracy of your answer: your estimated answer will either be greater or less than your actual answer.

Rounding to estimate does not allow you to subtract.

Rounding to estimate makes equations harder to calculate.

What is one of the problems associated with rounding to estimate?