NA4-3: Find fractions, decimals, and percentages of amounts expressed as whole numbers, simple fractions, and decimals.
This means students will understand that finding a decimal or percentage of an amount involves finding a fraction of that amount, for example 40% of 56 = 0.4 x 56 = 4 x 5.6 = 22.4. They should be able to solve problems of the form a/b x c = d (a,b,c and d are whole numbers), where any one of the numbers is not known, for example 4/7 x = 24 (Four-sevenths of what number is twenty-four?) or % of 76 = 19 (What percentage of seventy-six is nineteen?). Students should be able to multiply fractions with understanding, for example 2/3 x 3/5 = as two-thirds of four-fifths, and use their multiplicative understanding of place value to solve multiplication and division problems with simple decimals, for example 1.6 x 0.4 = as 16 x 4 ÷ 100 = 0.64 and 24 ÷ 0.3 = as 24 ÷ 3 x 10 = 80.