1. The vocabulary of numbers and operations • a ten = 10 units • one hundred = 10 tens = 100 units • one thousand = 10 hundreds = 100 tens = 1000 units • lower: smaller 15 < 45 reads 15 is less than 45 • higher: greater 59 > 34 reads 59 is greater than 34 • ascending order: from smallest to largest. "Growth" is when you grow. 23 < 54 < 67 < 75 These numbers are arranged in ascending order. • descending order: from largest to smallest 86 > 78 > 69 > 41 These numbers are arranged in descending order. • add: perform the operation that uses the + sign 52 + 24 is an addition. We say that we calculate the sum of the two numbers. • subtract: perform an operation that uses the sign - 37 - 28 is a subtraction. We say that we calculate the difference of two numbers. • multiply: perform the operation that uses the sign x 4 x 5 is a multiplication. We read: 5 times 4 or 4 multiplied by 5. We say that we calculate the product of the two numbers. • divide: perform the operation using the sign: 40:2 is a split. It reads 40 divided by 2, it means that we divide 40 into 2 equal parts. • Ask an operation: write it in column 67 + 48 It is a posed operation. If you are told "pose and perform", you must write the operation in columns and calculate the result. You will learn more words every year. They will have to be remembered and used.