Page 13 - steps 3b.pdf

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14
• Ways to add •••• I' a calculator • Double and halve • • A3 paper, red, blue
and green pencils
~;~t]t{~~ ~;~t]t{~~
[0 Try this.
I
"ffR ,
On your paper, rule a red line less than 15 cm long.
234 _ 200 + 30 + 4
+ 1 63 _ 1 00 + 60 + 3 6crn
300 + 90 + 7~ 397
Underneath the red line, rule a blue line twice as long
as the red line.
Underneath the blue line, rule a green line half as long
[JJ Write these in the same way. as the blue line. ~
a 236 + 253 b 182 + 217 c 130 + 318 rn
Do this lots of times, starting with red lines
d 464 + 32 e 343 + 156 267 + 121 of different lengths.
Pratical: ruling lines.
[]] Afterwards, complete this sentence.
[]] Check your answers with a calculator.
[gJ
When you double and then halve a length ...
CHALLENGE When you double and
rn Write these in the same way.
Design more pairs of loops like these. then halve a length
a 103 + 345 b 146 + 253
c 218 + 270 d 309 + 150 you have the length
p.frS-In e 241 + 258 f 181 + 317 you started with.
r !,@", ,@"' ,
234
+ 163 GJ Do these in any way you like. EIl [g] @QJ ~ Challenge
7 (4+3)
90 (30+60) a 347 + 52 b 235 + 30 "-@/ I
.
300 (200+100) c 144 + 254 d 304 + 85 I '@Y! ., Designing loops to
397 e 109 + 1 90 f 72 + 413 show halving and
doubling. (1/3 b,c,d)
1m I STEPS 3b:61 I STEPS 3b:7! m

rn [gJ b 146 d 30q f 181

+ 253 + 150 + 317
a 236-.200 + 30 + 6 b 182 -. 1 00 + 80 + 2 Check answers on q (6+3) q (q+O) 8 (1 +7)
+ 253-.200 + 50 + 3 + 217-.200 + 10 + 7 calculator. qO (40+50) 50 (0+50) qO (80+ 1 0)
400 + 80 + q -. 48q 300 + qO + q -. 3qq 300 (100+200) 400 (300+ 1 00) 400 (1 00+300)
c 130 -. 1 00 + 30 + 0 d 464-.400 + 60 + 4 [!] 3qq 4'6l.9 4q8
5
+ 318-.300 + 10 + 8 + 32-. 30 + 2 a 103 c 218 e 241
400 + 40 + 8 -.448 400 + qO + 6 -. 4q6 ~
+ 345 + 270 + 258
e 343-.300 + 40 + 3 f 267-.200 + 60 + 7 8 (3+5) 8 (8+0) q (1 +8) a 3qq b 265 c 3q8
+ 156 -. 1 00 + 50 + 6 + 121 -. 1 00 + 20 + 1 40 (0+40) 80 (10+70) qO (40+50)
400 + qO + q -.4qq 300 + 80 + 8 -. 388 400 (1 00+300) 400 (200+200) 400 (200+200) d 38q e 2qq f 485
448 488 4qq