Year 4 Addition & Subtraction - Problem-Solving Investigations

These in-depth maths investigations are open-ended problem solving activities for Year 4 children.

In-depth Investigation: Make 100
Given a pattern of four one-digit numbers, children attempt to make a total of exactly 100.

In-depth Investigation: Total £10
Using only digits 1-9 without the ‘5’, children find all possible pairs of amounts to make £10.

In-depth Investigation: Cats and Dogs
Children work to solve a puzzle involving adding two 3-digit numbers. They find several possible solutions, and then invent their own puzzle.

In-depth Investigation: Hole-y Subtractions
Children create 3-digit palindromic numbers with a ‘hole’ (i.e. a zero) in the middle. They subtract 3-digit numbers with equal numbers of 1s, 10s and 100s and identify patterns in their answers.

In-depth Investigation: Present Prices
Children use logic and addition, along with some trial and improvement to solve a problem involving money.

In-depth Investigation: Wonderful 1089!
Children add two 3-digit numbers and subtract a pair of 3-digit numbers to find patterns. They use mathematical reasoning to begin to explain what they find.

In-depth Investigation: Mobile Subtractions
Children select 3 contiguous numbers from a mobile phone display and create a subtraction.

In-depth Investigation: Subtraction Trios
Children look for patterns in answers when subtracting 3-digit numbers from 4-digit numbers with consecutive digits.

In-depth Investigation: Prime Addition Squares
Children add sets of three 3-digit numbers to find patterns in a magic square based on prime numbers.

These investigations will develop maths meta-skills, support open-ended questioning and logical reasoning, and enable children to learn to think mathematically and articulate mathematical ideas.

These problem-solving investigations come from our Year 4 Maths Blocks. Each Hamilton maths block contains a complete set of planning and resources to teach a term’s worth of objectives for one of the National Curriculum for England’s maths areas.