Enrichment

• Neighbour numbers and round numbersOne before and one after14 − 1
• Fact familiesTwo plus sums and two minus sums7 + 8
• Repeated adding to timesTimes is repeated adding5 + 5 + 5 = ? × 5
• Roman numeralsRoman numerals: I, V, X, L, C, D, M10 + 5 + 1
• Squares, roots and powersPowers and square roots√36
• Breaking down into prime factorsBreak down into prime factors2 × 2 × 3
• Filling a fraction to 1Fill to 1 whole29 + ? = 1
• Working out the averageAdd and divide by how many6 + 8 + 10
• Time zones and world timeTime zones: earlier to the west, later to the east15 − 5
• Converting currenciesConvert with an exchange rate20 × 1.25
• Counting combinationsMultiply the number of choices3 × 4
• Working back to old priceCalculate back to 100%75 × 100