I can halve all numbers up to 100
eg.
½ of 56 is 28
half of 68 = 34
50% of 19 = 9½
45 ÷ 2 = 22.5
Tip! Partition the number:
½ of 56… ½ of 50 = 25
½ of 6 = 3
25 + 3 = 28
Date achieved:
I can double numbers up to 1000
eg.
Double 453 is 906
214 x 2 = 428
2 x 765 = 1530
Tip! Partition the number:
2 x 765…
2 x 700 = 1400
2 x 65 = 130
Date achieved:
1400 + 130 = 1530
I can double decimal numbers with tenths
eg.
Double 23.4 is 46.8
65.2 x 2 = 130.4
2 x 53.7 = 107.4
Tip! Partition the number:
2 x 53.7…
2 x 53 = 106
2 x 0.7 = 1.4
106 + 1.4 = 107.4
Date achieved:
I can double decimal numbers with hundredths
eg.
Double 32.21 is 64.42
£46.22 x 2 = £92.44
2 x 14.78 = 29.56
Tip! Think about it as money!
2 x £14.78…
2 x £14 = £28 2 x 78p = £1.56
£28 + £1.56 = £29.56
Date achieved:
I can halve decimal numbers with units and tenths
eg.
Half of 4.2 is 2.1
8.6 ÷ 2 = 4.3
½ of 6.3 is 3.15
Tip! A zero in the hundredths column can help…
½ of 6.3 = ½ of 6.30 = 3.15
Date achieved:
I can double multiples of 10 to 1000
eg.
Double 340 is 680
2 x 860 = 1720
270 x 2 = 540
Tip! Double the significant digits first...
270 x 2…
27 x 2 = 54
so 270 x 2 = 540
Date achieved:
I can halve multiples of 10 to 1000
eg.
Half of 860 is 430
970 ÷ 2 = 485
650 halved is 325
Tip! Partition the number
50% of 970
50% of 900 = 450
50% of 70 = 35
450 + 35 = 485
Date achieved:
I can double multiples of 100 to 10,000
eg.
Double 4500 is 9000
2 x 6300 = 12,600
7600 x 2 = 15,200
Tip! Double the significant digits first...
7600 x 2…
76 x 2 = 152
so 7600 x 2 = 15200
Date achieved:
I can halve multiples of 100 to 10,000
eg.
Half of 3200 is 1600
5800 ÷ 2 = 2900
7900 halved is 3950
Tip! Partition the number
½ of 7900
½ of 7000= 3500 ½ of 900 = 450
3500 + 450 = 3950
Date achieved:
I can multiply any two digit number by a single digit
eg.
34 x 8 = 272
5 x 76 = 380
7 x 29 = 203
Tips! There are lots of tips for
multiplying by a single digit - and
they all use skills you already
know! Here are some - you must
know them all to get Gold!
x 4: double and double again
17 x 4: 17, 34, 68
x 5: multiply by 10 and halve
94 x 5
 94 x 10 = 940
x 8: double, double double!
8 x 56: 56, 112, 224, 448
 half of 940 is 470
x9: multiply by 10 and take one lot away
28 x 9
 28 x 10 = 280
 280 - 28 = 252
Date achieved:
I can multiply or divide any number by 10 or 100
eg.
43.2 x 10 = 432
6.02 x 100 = 602
432 ÷ 100 = 4.32
6.02 ÷ 100 = 0.0602
Tip! Move the digits along through the columns
Multiply Left, Divide Right
Date achieved: