# NA2-1: Use simple additive strategies with whole numbers and fractions.

Elaboration on this Achievement Objective

This means students will learn to treat whole numbers as units of ones that can be split and recombined to make calculations easier. Additive strategies are about a type of thinking not the operation of addition. So additive strategies can be applied to addition (for example, 47 + 38 is 50 + 40 – 5), subtraction (for example, 74 – 8 = as 74 – 4 – 4 = ), multiplication (for example, 4 x 4 = as 4 + 4 + 4 + 4 = , which is 8 + 8 = ), division (for example, 18 ÷ 3 = , as 5 + 5 + 5 = 15 so 6 + 6 + 6 = 18). Additive strategies may also be applied to finding fractions of sets particularly halves, thirds, quarters, fifths, eighths and tenths. Level Two corresponds to students being proficient at the Early Additive stage of the number framework.

Teaching resources for this Achievement Objective

This is an activity based on the picture book 365 Penguins

Students will be able to relate the features of the calendar to their number knowledge. Students will be able to demonstrate how grouping is efficient way to organise their thinking and operating with larger numbers.

Picture book activities

Number and Algebra

Level Two

This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework.

add compatible numbers

Figure It Out activities

Number and Algebra

Level Two

This is a level 2 number link activity from the Figure It Out series. It relates to Stage 5 of the Number Framework. A PDF of the student activity is included.

use number lines to show mental strategies for addition and subtraction problems

Figure It Out activities

Number and Algebra

Level Two

Solve addition and subtraction problems by going through tens.

Numeracy activities

Number and Algebra

Level Two

Solve addition and subtraction problems by using place value partitioning.

Numeracy activities

Number and Algebra

Level Two

Change start-unknown problems to change-unknown problems. Solve addition and subtraction problems by compensating with tidy numbers.

Numeracy activities

Number and Algebra

Level Two

Manipulate numbers (using the number operations) to obtain a given number; Change a word problem into an arithmetic problem; Devise and use problem solving strategies to explore situations mathematically (guess and check, be systematic). Report the results of mathematical explorations concisely and...

Problem solving activities

Number and Algebra

Level Two

This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework. A PDF of the student activity is included.

know number of tens in numbers up to 100 use mental strategies to add numbers

Figure It Out activities

Number and Algebra

Level Two

The purpose of this activity is to engage students in carrying out a division, where the solution is not a whole number.

Rich learning activities

Number and Algebra

Level Two

This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework.

add single digit numbers

Figure It Out activities

Number and Algebra

Level Two

Find unit fractions of sets using addition facts.

Numeracy activities

Number and Algebra

Level Two

This is a level 2 number link activity from the Figure It Out series. It relates to Stage 5 of the Number Framework. A PDF of the student activity is included.

solve addition problems using number lines

Figure It Out activities

Number and Algebra

Level Two

This is an activity based on the picture book A Remainder of One

Students will be able to model the answer to division problems by equal sharing as a set of equal groups and a whole number remainder. Students will be able to express a division problem as an equation and explain what each number in the equation represents in relation to their model.

Picture book activities

Number and Algebra

Level Two

In this unit students are given the opportunity to explore multiplication concepts using arrays. The use of multiple strategies and the sharing of strategies is encouraged, in group and whole class situations.

Solve multiplication problems by using skip counting or additive strategies. Interpret and solve multiplication story problems.

Units of Work

Number and Algebra

Level Two

This interactive learning module supports students to explore using compatible numbers to 100 to solve addition and subtraction problems.

Exploring addition and subtraction using compatible numbers. Explaining, showing and writing mathematical ideas.

Student e-Ako

Number and Algebra

Level Two

This interactive learning module supports students to explore using partitioning to solve addition and subtraction problems.

Exploring addition and subtraction using partitioning. Explaining, showing and writing mathematical ideas.

Student e-Ako

Number and Algebra

Level Two

This interactive learning module supports students to explore using partitioning and place value to solve two-digit addition and subtraction problems.

Exploring addition and subtraction using partitioning. Using place value knowledge of tens and ones to solve problems. Explaining, showing and writing mathematical ideas.

Student e-Ako

Number and Algebra

Level Two

This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework. A PDF of the student activity is included.

use additive strategies (back through ten) to solve subtraction problems

Figure It Out activities

Number and Algebra

Level Two

This is a level 2 number strand activity from the Figure It Out series. A PDF of the student activity is included.

solve problems using additive strategies

Figure It Out activities

Number and Algebra

Level Two

The purpose of this activity is to engage students in using a non-standard unit to give a measurement involving fractions.

Rich learning activities

Number and Algebra

Level Two

The purpose of this activity is to engage students in using their number knowledge and skills to solve a problem requiring partitioning.

Rich learning activities

Number and Algebra

Level Two

This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework. A PDF of the student activity is included.

use compatible numbers to 10 to solve addition problems

Figure It Out activities

Number and Algebra

Level Two

This is a level (2+ to 3+) mathematics in science contexts activity from the Figure It Out series. A PDF of the student activity is included.

Students will: add and subtract whole numbers. Students should discover that: to win, the sum of the squares they land on must be greater than or equal to zero.

Figure It Out activities

Number and Algebra

Level Two

The purpose of this activity is to develop useful strategies for mental calculation when estimating possible addition solutions.

estimate the sum or difference between numbers.

Numeracy activities

Number and Algebra

Level Two