Divide by three-digit number (continued) 1.1. Knowledge to remember a) 41535 : 195 = ? Sort in order from left to right: 415 divided by 195 gives 2, write 2 ; 2 times 5 equals 10 ; 15 minus 10 equals 5, write 5 remember 1 ; 2 times 9 equals 18, plus 1 equals 19 ; 21 minus 19 equals 2, write 2 remember 2 ; 2 times 1 equals 2, add 2 equals 4 ; … [Read more...] about Divide by three-digit number (continued)

# Chapter 2: Four Operations With Natural Numbers. Geometry

## Divide by three digit number

Divide by three digit number 1.1. Knowledge to remember a) 1944 : 162 Sort in order from left to right: 194 divided by 162 gets 1, write 1 ; 1 times 2 equals 2 ; 4 minus 2 equals 2, write 2 ; 1 times 6 equals 6 ; 9 minus 6 equals 3, write 3 ; 1 times 1 equals 1 ; 1 minus 1 equals 0, write 0. Down 4, got 324 ; 324 divided by 162 … [Read more...] about Divide by three digit number

## The quotient has the digit 0

The quotient has the digit 0 1.1. Knowledge to remember a) 9450 : 35 = ? Sort in order from left to right: 94 divided by 35 gives 2, write 2 ; 2 times 5 equals 10; 14 minus 10 equals 4, write 4 remember 1 ; 2 times 3 equals 6, adding 1 equals 7 ; 9 minus 7 equals 2, write 2. Down 5, get 245 ; 245 divided by 35 gives 7, write 7 ; … [Read more...] about The quotient has the digit 0

## Divide two numbers ending in 0

Divide two numbers ending in 0 1.1. Knowledge to remember a) 320 : 40 = ? 320 : 40 = 320 : (10 × 4) = 320 : 10 : 4 = 32 : 4 = 8 320 : 40 = 8 Comment : 320 : 40 = 32 : 4. When doing the division 320 : 40, we can delete the same zero at the end of the … [Read more...] about Divide two numbers ending in 0

## Divide a product by a number

Divide a product by a number 1.1. Knowledge to remember a) Calculate and compare the values of the expressions: (9 × 15) : 3 9 × (15 : 3) (9 : 3) × 15 We have : (9 × 15) : 3 = 135 : 3 = 45 9 × (15 : 3) = 9 × 5 = 45 (9 : 3) × 15 = 3 × 15 = 45 So : (9 × 15) : 3 = 9 x (15 : 3) = (9 : 3) × 15 b) Calculate and compare … [Read more...] about Divide a product by a number

## Divide a number by a product

Divide a number by a product 1.1. Knowledge to remember Calculate and compare the values of the expressions: 24 : (3 × 2) 24 : 3 : 2 24 : 2 : 3 We have: 24 : (3×2) = 24 : 6 = 4 24 : 3 : 2 = 8 : 2 = 4 24 : 2 : 3 = 12 : 3 = 4 So: 24 : (3 × 2) = 24 : 3 : 2 = 24 : 2 : 3 When we divide a number by a product of two factors, we … [Read more...] about Divide a number by a product

## Divide by one digit number

Divide by one digit number 1.1. Knowledge to remember a) 128472 : 6 = ? Sort in order from left to right: 12 divided by 6 get 2, write 2 ; 2 times 6 equals 12; 12 minus 12 equals 0, Lower 8 ; 8 divided by 6 get 1, write 1 ; 1 times 6 equals 6; 8 minus 6 equals 2, write 2. Down 4, get 24; 24 divided by 6 get 4, write 4 ; 4 times 6 … [Read more...] about Divide by one digit number

## Divide a sum by a number

Divide a sum by a number 1.1. Knowledge to remember Calculate and compare the values of two expressions: (35 + 21) : 7 and 35 : 7 + 21 : 7 We have : (35 + 21) : 7 = 56 : 7 = 8 35 : 7 + 21 : 7 = 5 + 3 = 8 So : (35 + 21) : 7 = 35 : 7 + 21 : 7 When dividing a sum by a number, if the terms of the sum are all divisible by the divisor, … [Read more...] about Divide a sum by a number

## Multiply by a three-digit number

Multiply by a three-digit number 1.1. Multiply by a three-digit number 164 × 123 = ? a) We can calculate the following: 164 × 123 = 164 × ( 100 + 20 + 3) = 164 × 100 + 164 × 20 + 164 × 3 = 16400 + 3280 + 492 = 20172 b) Usually we set and calculate as follows: 3 times 4 equals 12, write 2 remember 1 ; … [Read more...] about Multiply by a three-digit number

## Introduction to mental multiplication by two-digit numbers by 11

Introduction to mental multiplication by two-digit numbers by 11 1.1. Knowledge to remember a) 27 × 11 = ? Set and calculate: \(\begin{array}{l}\underline { \times \begin{array}{*{20}{c}}{27}\\{11}\end{array}} \\\underline {\begin{array}{*{20}{c}}{\,\,\,27}\\{27\,\,\,}\end{array}} \\297\end{array}\) Two eigenproducts are equal to 27. When adding two … [Read more...] about Introduction to mental multiplication by two-digit numbers by 11