# NA4-2: Understand addition and subtraction of fractions, decimals, and integers.

This means students will understand decimals as fractions, and be able to express decimals in fraction form and vice versa, for example 2.47 = 2 + 4 tenths + 7 hundredths (2 + 4/10 + 7/100 ), or 247 hundredths (247/100). They should solve addition and subtraction problems with decimals and with fractions (denominators must be related multiples), for example 13.2 – 5.79 = 7.41 and 3/4 + 7/8 = 13/8 = 1 5/8 by choosing appropriately from mental, machine and paper methods. Students should apply the strategies used for mental calculation with whole numbers to addition and subtraction of decimals, including standard place value, compensation after rounding, and applying inverse (reversing). Formal written algorithms for decimal addition and subtraction should be taught at Level Four **after students have the place value knowledge required to understand them.**

Solve addition and subtraction problems with integers (positive and negative numbers).

Solve problems that involve adding and subtracting decimals.

- Identify a utility need or opportunity within the school and plan a response .
- Create a design incorporating key attributes identified.
- Investigate quality and comparative costs of possible construction materials.
- Cost ‘fit for purpose’ construction materials and prepare a budget.
- Draw plans300

- Understand and describe proportion using the language of mathematics.
- Make accurate metric length measurements.
- Understand the principles of scale.
- Understand that the value of the scale factor of a reduction is less than 1 and for an enlargement is greater than 1.
- Understand that the scale300

- Understanding the place value structure of decimal numbers.
- Using partitioning to solve addition problems to three decimal places.

- Understanding the place value structure of decimal numbers.
- Using addition to solve subtraction problems to three decimal places.

- Using a number line to solve subtraction problems to three decimal places.

- Estimating answers to decimal addition and subtraction problems.
- Solving context-based addition and subtraction problems.

- Understanding where positive and negative numbers belong on a number line.
- Understanding addition and subtraction of integers.

- Understanding addition and subtraction of integers.
- Recording sums involving positive and negative numbers.

use addition to sovle money problems

use multiplication and division to solve problems

find percentage of a number

solve problems involving ratios

find fraction of a number

multiply decimals with multiples of ten

operate on fractions and decimals

find fractions of money amounts

add money amounts

find a percentage of a decimal number

solve addition and subtraction problems

compare prices by using proportions

solve addition and subtraction problems involving integers

Addition and subtraction of fractions with unlike denominators

convert unlike units in order to add and subtract them

Use compatible numbers to solve addition problems with decimal fractions (tenths) (Exercises 1-5)

Use compatible numbers to solve subtraction problems with decimal fractions (tenths) (Exercise 6)

- Name the fraction for a given Cuisenaire rod with reference to one (whole).
- Give the relationship between one Cuisenaire Rod and another, especially when one rod is a fraction of the other.
- Add and subtract fractions by expressing fractions as equivalents with the same denominator.
- Order300

find fractions of time

calculate average speed

interpret timetable