Step-by-step Maths Level 4: Counting in fifties
Part of the Step-by-step Maths Level 4 counting and place value to 10000 chapter. Chapter overview · whole chapter on one page
Counting in fifties
Fifty is half of a hundred. Counting in fifties gives 50, 100, 150, 200 and so on.
Each hundred has two fifties in it: the number ends in 50 or 00.
Key ideas
- Each fifty ends in 50 or 00.
- Fifty is half of a hundred.
- Count in steps of 50 to find the answer.
Method. Find the step between the numbers, then count on to fill the gap.
- Find the step. The numbers go up by 50 each time.1900 - 1850 = 50
- Count on from 1900. Add 50 to get the missing number.1900 + 50 = 1950
- Write the missing number. It fits the pattern.1950
Check. Check: 1950 + 50 = 2000.
Watch out. Fifties go up in steps of 50, so the ones and tens count in fifties.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.3250
- Add 50 each time. Each count moves by the same step.3250 + 50 = 3300
- Add 50 each time. Each count moves by the same step.3300 + 50 = 3350
- Add 50 each time. Each count moves by the same step.3350 + 50 = 3400
- Add 50 each time. Each count moves by the same step.3400 + 50 = 3450
- Write the answer. This is the last number we reached.3450
Check. Count the steps back: 3450 - 200 = 3250.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.6000
- Take 50 each time. Each count moves by the same step.6000 - 50 = 5950
- Take 50 each time. Each count moves by the same step.5950 - 50 = 5900
- Take 50 each time. Each count moves by the same step.5900 - 50 = 5850
- Write the answer. This is the last number we reached.5850
Check. Count the steps back: 5850 + 150 = 6000.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Watch out
Watch out. After 1950 comes 2000, not 1960. Fifties always end in 00 or 50.
Exam tip
Grown-up tip. Ask the child to count in fifties from a multiple of 50, such as 3250, then say the next number before you do.
Exercise 1C Practice: counting in fifties
Non-calculatorMethod. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.2000
- Add 50 each time. Each count moves by the same step.2000 + 50 = 2050
- Add 50 each time. Each count moves by the same step.2050 + 50 = 2100
- Add 50 each time. Each count moves by the same step.2100 + 50 = 2150
- Add 50 each time. Each count moves by the same step.2150 + 50 = 2200
- Write the answer. This is the last number we reached.2200
Check. Count the steps back: 2200 - 200 = 2000.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.4200
- Add 50 each time. Each count moves by the same step.4200 + 50 = 4250
- Add 50 each time. Each count moves by the same step.4250 + 50 = 4300
- Add 50 each time. Each count moves by the same step.4300 + 50 = 4350
- Write the answer. This is the last number we reached.4350
Check. Count the steps back: 4350 - 150 = 4200.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.2950
- Add 50 each time. Each count moves by the same step.2950 + 50 = 3000
- Add 50 each time. Each count moves by the same step.3000 + 50 = 3050
- Add 50 each time. Each count moves by the same step.3050 + 50 = 3100
- Write the answer. This is the last number we reached.3100
Check. Count the steps back: 3100 - 150 = 2950.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.6350
- Take 50 each time. Each count moves by the same step.6350 - 50 = 6300
- Take 50 each time. Each count moves by the same step.6300 - 50 = 6250
- Take 50 each time. Each count moves by the same step.6250 - 50 = 6200
- Write the answer. This is the last number we reached.6200
Check. Count the steps back: 6200 + 150 = 6350.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.7250
- Take 50 each time. Each count moves by the same step.7250 - 50 = 7200
- Take 50 each time. Each count moves by the same step.7200 - 50 = 7150
- Take 50 each time. Each count moves by the same step.7150 - 50 = 7100
- Write the answer. This is the last number we reached.7100
Check. Count the steps back: 7100 + 150 = 7250.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.4650
- Take 50 each time. Each count moves by the same step.4650 - 50 = 4600
- Take 50 each time. Each count moves by the same step.4600 - 50 = 4550
- Write the answer. This is the last number we reached.4550
Check. Count the steps back: 4550 + 100 = 4650.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.4000
- Add 50 each time. Each count moves by the same step.4000 + 50 = 4050
- Add 50 each time. Each count moves by the same step.4050 + 50 = 4100
- Add 50 each time. Each count moves by the same step.4100 + 50 = 4150
- Write the answer. This is the last number we reached.4150
Check. Count the steps back: 4150 - 150 = 4000.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Find the step between the numbers, then count on to fill the gap.
- Find the step size from two numbers that are next to each other. The step is the same all the way along.6650 - 6600 = 50
- Count from the number before the gap. Add the step to get the missing number.6550 + 50 = 6600
- Write the missing number. It fits the pattern.6600
Check. Check: 6600 + 50 is the next number, 6650.
Watch out. Look at the numbers either side of the gap. The step is the same each time.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.3700
- Add 50 each time. Each count moves by the same step.3700 + 50 = 3750
- Add 50 each time. Each count moves by the same step.3750 + 50 = 3800
- Add 50 each time. Each count moves by the same step.3800 + 50 = 3850
- Add 50 each time. Each count moves by the same step.3850 + 50 = 3900
- Add 50 each time. Each count moves by the same step.3900 + 50 = 3950
- Write the answer. This is the last number we reached.3950
Check. Count the steps back: 3950 - 250 = 3700.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.8000
- Add 50 each time. Each count moves by the same step.8000 + 50 = 8050
- Add 50 each time. Each count moves by the same step.8050 + 50 = 8100
- Write the answer. This is the last number we reached.8100
Check. Count the steps back: 8100 - 100 = 8000.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Find the step between the numbers, then count on to fill the gap.
- Find the step size from two numbers that are next to each other. The step is the same all the way along.5950 - 5900 = 50
- Count from the number before the gap. Add the step to get the missing number.5900 + 50 = 5950
- Write the missing number. It fits the pattern.5950
Check. Check: 5950 + 50 is the next number, 6000.
Watch out. Look at the numbers either side of the gap. The step is the same each time.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.2400
- Take 50 each time. Each count moves by the same step.2400 - 50 = 2350
- Take 50 each time. Each count moves by the same step.2350 - 50 = 2300
- Take 50 each time. Each count moves by the same step.2300 - 50 = 2250
- Take 50 each time. Each count moves by the same step.2250 - 50 = 2200
- Take 50 each time. Each count moves by the same step.2200 - 50 = 2150
- Write the answer. This is the last number we reached.2150
Check. Count the steps back: 2150 + 250 = 2400.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Find the step between the numbers, then count on to fill the gap.
- Find the step size from two numbers that are next to each other. The step is the same all the way along.7500 - 7450 = 50
- Count from the number before the gap. Add the step to get the missing number.7400 + 50 = 7450
- Write the missing number. It fits the pattern.7450
Check. Check: 7450 + 50 is the next number, 7500.
Watch out. Look at the numbers either side of the gap. The step is the same each time.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.8900
- Take 50 each time. Each count moves by the same step.8900 - 50 = 8850
- Take 50 each time. Each count moves by the same step.8850 - 50 = 8800
- Write the answer. This is the last number we reached.8800
Check. Count the steps back: 8800 + 100 = 8900.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Count in steps of the same size, one step at a time.
- Start at the first number. It is where we begin.5850
- Take 50 each time. Each count moves by the same step.5850 - 50 = 5800
- Take 50 each time. Each count moves by the same step.5800 - 50 = 5750
- Take 50 each time. Each count moves by the same step.5750 - 50 = 5700
- Take 50 each time. Each count moves by the same step.5700 - 50 = 5650
- Write the answer. This is the last number we reached.5650
Check. Count the steps back: 5650 + 200 = 5850.
Watch out. Each step adds or takes away the same amount. Do not start counting again from the beginning.
Method. Find the step between the numbers, then count on to fill the gap.
- Find the step size from two numbers that are next to each other. The step is the same all the way along.8350 - 8300 = 50
- Count from the number before the gap. Add the step to get the missing number.8300 + 50 = 8350
- Write the missing number. It fits the pattern.8350
Check. Check: 8350 + 50 is the next number, 8400.
Watch out. Look at the numbers either side of the gap. The step is the same each time.